Align with current tool proxy on linux beta/stable

In order to align with the current configuration in tool proxy, the platform should be restricted to linux and the channels should be restricted to beta/stable. These configurations already exist in tool proxy, so this change reflects that config.

Change-Id: Idc460d490a317a8347ec52f48d30936904b53612
Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/42280
Reviewed-by: Casey Hillers <chillers@google.com>
Commit-Queue: Jesse Seales <jseales@google.com>
diff --git a/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3-4.5.pre_betaFalse.json b/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3-4.5.pre_betaFalse.json
index 1d7cdd9..58cc49e 100644
--- a/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3-4.5.pre_betaFalse.json
+++ b/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3-4.5.pre_betaFalse.json
@@ -274,7 +274,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -319,7 +319,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -350,7 +350,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -376,7 +376,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "RELEASE_CHANNEL": "beta",
       "REL_HASH": "deadbeef",
@@ -436,7 +436,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -481,7 +481,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -512,7 +512,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -538,7 +538,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "RELEASE_CHANNEL": "beta",
       "REL_HASH": "",
       "REPO": "engine",
diff --git a/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3-4.5.pre_beta_force.json b/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3-4.5.pre_beta_force.json
index 1d7cdd9..58cc49e 100644
--- a/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3-4.5.pre_beta_force.json
+++ b/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3-4.5.pre_beta_force.json
@@ -274,7 +274,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -319,7 +319,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -350,7 +350,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -376,7 +376,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "RELEASE_CHANNEL": "beta",
       "REL_HASH": "deadbeef",
@@ -436,7 +436,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -481,7 +481,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -512,7 +512,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -538,7 +538,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "RELEASE_CHANNEL": "beta",
       "REL_HASH": "",
       "REPO": "engine",
diff --git a/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3-4.5.pre_stableFalse.json b/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3-4.5.pre_stableFalse.json
index 6c1a14d..1cdb0c3 100644
--- a/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3-4.5.pre_stableFalse.json
+++ b/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3-4.5.pre_stableFalse.json
@@ -274,7 +274,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -319,7 +319,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -350,7 +350,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -376,7 +376,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "RELEASE_CHANNEL": "stable",
       "REL_HASH": "deadbeef",
@@ -436,7 +436,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -481,7 +481,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -512,7 +512,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -538,7 +538,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "RELEASE_CHANNEL": "stable",
       "REL_HASH": "",
       "REPO": "engine",
diff --git a/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3-4.5.pre_stable_force.json b/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3-4.5.pre_stable_force.json
index 6c1a14d..1cdb0c3 100644
--- a/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3-4.5.pre_stable_force.json
+++ b/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3-4.5.pre_stable_force.json
@@ -274,7 +274,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -319,7 +319,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -350,7 +350,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -376,7 +376,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "RELEASE_CHANNEL": "stable",
       "REL_HASH": "deadbeef",
@@ -436,7 +436,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -481,7 +481,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -512,7 +512,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -538,7 +538,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "RELEASE_CHANNEL": "stable",
       "REL_HASH": "",
       "REPO": "engine",
diff --git a/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3_betaFalse.json b/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3_betaFalse.json
index c47e7d9..a4d1c9e 100644
--- a/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3_betaFalse.json
+++ b/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3_betaFalse.json
@@ -274,7 +274,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -319,7 +319,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -350,7 +350,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -376,7 +376,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "RELEASE_CHANNEL": "beta",
       "REL_HASH": "deadbeef",
@@ -436,7 +436,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -481,7 +481,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -512,7 +512,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -538,7 +538,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "RELEASE_CHANNEL": "beta",
       "REL_HASH": "",
       "REPO": "engine",
diff --git a/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3_beta_force.json b/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3_beta_force.json
index c47e7d9..a4d1c9e 100644
--- a/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3_beta_force.json
+++ b/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3_beta_force.json
@@ -274,7 +274,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -319,7 +319,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -350,7 +350,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -376,7 +376,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "RELEASE_CHANNEL": "beta",
       "REL_HASH": "deadbeef",
@@ -436,7 +436,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -481,7 +481,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -512,7 +512,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -538,7 +538,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "RELEASE_CHANNEL": "beta",
       "REL_HASH": "",
       "REPO": "engine",
diff --git a/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3_stableFalse.json b/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3_stableFalse.json
index 833b5d0..490aeb1 100644
--- a/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3_stableFalse.json
+++ b/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3_stableFalse.json
@@ -274,7 +274,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -319,7 +319,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -350,7 +350,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -376,7 +376,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "RELEASE_CHANNEL": "stable",
       "REL_HASH": "deadbeef",
@@ -436,7 +436,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -481,7 +481,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -512,7 +512,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -538,7 +538,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "RELEASE_CHANNEL": "stable",
       "REL_HASH": "",
       "REPO": "engine",
diff --git a/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3_stable_force.json b/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3_stable_force.json
index 833b5d0..490aeb1 100644
--- a/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3_stable_force.json
+++ b/recipes/release/release_publish.expected/flutter-2.8-candidate.9_1.2.3_stable_force.json
@@ -274,7 +274,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -319,7 +319,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -350,7 +350,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "REVISION": "12345abcde12345abcde12345abcde12345abcde",
       "SDK_CHECKOUT_PATH": "[START_DIR]/flutter"
@@ -376,7 +376,7 @@
       "LUCI_BRANCH": "",
       "LUCI_CI": "True",
       "LUCI_PR": "",
-      "OS": "darwin",
+      "OS": "linux",
       "PUB_CACHE": "[START_DIR]/.pub-cache",
       "RELEASE_CHANNEL": "stable",
       "REL_HASH": "deadbeef",
@@ -436,7 +436,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -481,7 +481,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -512,7 +512,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "REVISION": ""
     },
     "env_prefixes": {
@@ -538,7 +538,7 @@
       "LUCI_CI": "True",
       "LUCI_PR": "",
       "LUCI_WORKDIR": "[START_DIR]",
-      "OS": "darwin",
+      "OS": "linux",
       "RELEASE_CHANNEL": "stable",
       "REL_HASH": "",
       "REPO": "engine",
diff --git a/recipes/release/release_publish.py b/recipes/release/release_publish.py
index 94cf63e..791dcd5 100644
--- a/recipes/release/release_publish.py
+++ b/recipes/release/release_publish.py
@@ -47,7 +47,7 @@
   release_channel = api.properties.get('release_channel')
   # default to False force push
   force = False if api.runtime.is_experimental else api.properties.get('force', False)
-  assert git_branch and tag and release_channel
+  assert git_branch and tag and release_channel in ('stable', 'beta')
 
   flutter_checkout = api.path['start_dir'].join('flutter')
   engine_checkout = api.path['start_dir'].join('engine')
@@ -57,9 +57,9 @@
   # Validate the given tag is correctly formatted for either stable or latest
   assert isValidTag(tag)
 
-  # This recipe should only be executed on linux or mac machines to
-  # guard against Windows git issues
-  assert api.platform.is_linux or api.platform.is_mac
+  # This recipe is only able to be triggered on linux, and the other platforms
+  # are not necessary
+  assert api.platform.is_linux
 
   with api.step.nest('checkout flutter release branch'):
     flutter_rel_hash = api.repo_util.checkout(
@@ -134,7 +134,7 @@
                   tag,
                   release_channel,
                   '_force' if force=='True' else 'False'
-              ), api.platform('mac', 64),
+              ), api.platform('linux', 64),
               api.properties(
                   git_branch='flutter-2.8-candidate.9',
                   tag=tag,