Only treat an explicit release_build = string true as true.

Bug: https://github.com/flutter/flutter/issues/168088
Change-Id: I888305292945a8cacfc4722065d6b69a147e545a
Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/65000
Reviewed-by: Jason Simmons <jsimmons@google.com>
Commit-Queue: Matan Lurey <matanl@google.com>
diff --git a/recipes/release/release_builder.expected/base_linux_beta.json b/recipes/release/release_builder.expected/base_linux_beta.json
index 40b5532..5cda580 100644
--- a/recipes/release/release_builder.expected/base_linux_beta.json
+++ b/recipes/release/release_builder.expected/base_linux_beta.json
@@ -289,7 +289,7 @@
       "@@@STEP_LOG_LINE@json.output@      \"name\": \"linux one\",@@@",
       "@@@STEP_LOG_LINE@json.output@      \"properties\": {@@@",
       "@@@STEP_LOG_LINE@json.output@        \"$flutter/osx_sdk\": \"{\\\"sdk_version\\\": \\\"14a5294e\\\"}\",@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"release_build\": true@@@",
+      "@@@STEP_LOG_LINE@json.output@        \"release_build\": \"true\"@@@",
       "@@@STEP_LOG_LINE@json.output@      },@@@",
       "@@@STEP_LOG_LINE@json.output@      \"recipe\": \"engine/something\"@@@",
       "@@@STEP_LOG_LINE@json.output@    },@@@",
diff --git a/recipes/release/release_builder.expected/base_linux_beta_monorepo.json b/recipes/release/release_builder.expected/base_linux_beta_monorepo.json
index 40b5532..5cda580 100644
--- a/recipes/release/release_builder.expected/base_linux_beta_monorepo.json
+++ b/recipes/release/release_builder.expected/base_linux_beta_monorepo.json
@@ -289,7 +289,7 @@
       "@@@STEP_LOG_LINE@json.output@      \"name\": \"linux one\",@@@",
       "@@@STEP_LOG_LINE@json.output@      \"properties\": {@@@",
       "@@@STEP_LOG_LINE@json.output@        \"$flutter/osx_sdk\": \"{\\\"sdk_version\\\": \\\"14a5294e\\\"}\",@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"release_build\": true@@@",
+      "@@@STEP_LOG_LINE@json.output@        \"release_build\": \"true\"@@@",
       "@@@STEP_LOG_LINE@json.output@      },@@@",
       "@@@STEP_LOG_LINE@json.output@      \"recipe\": \"engine/something\"@@@",
       "@@@STEP_LOG_LINE@json.output@    },@@@",
diff --git a/recipes/release/release_builder.expected/base_linux_main.json b/recipes/release/release_builder.expected/base_linux_main.json
index 9e487c3..43db4a6 100644
--- a/recipes/release/release_builder.expected/base_linux_main.json
+++ b/recipes/release/release_builder.expected/base_linux_main.json
@@ -290,7 +290,7 @@
       "@@@STEP_LOG_LINE@json.output@      \"name\": \"linux one\",@@@",
       "@@@STEP_LOG_LINE@json.output@      \"properties\": {@@@",
       "@@@STEP_LOG_LINE@json.output@        \"$flutter/osx_sdk\": \"{\\\"sdk_version\\\": \\\"14a5294e\\\"}\",@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"release_build\": true@@@",
+      "@@@STEP_LOG_LINE@json.output@        \"release_build\": \"true\"@@@",
       "@@@STEP_LOG_LINE@json.output@      },@@@",
       "@@@STEP_LOG_LINE@json.output@      \"recipe\": \"engine/something\"@@@",
       "@@@STEP_LOG_LINE@json.output@    },@@@",
@@ -403,7 +403,7 @@
       }
     },
     "name": "launch builds.schedule",
-    "stdin": "{\"requests\": [{\"scheduleBuild\": {\"builder\": {\"bucket\": \"try\", \"builder\": \"Linux Engine Drone\", \"project\": \"prod\"}, \"dimensions\": [{\"key\": \"os\", \"value\": \"Linux\"}], \"exe\": {\"cipdVersion\": \"refs/heads/main\"}, \"experimental\": \"NO\", \"experiments\": {\"luci.buildbucket.parent_tracking\": false}, \"fields\": \"builder,createTime,createdBy,critical,endTime,id,infra,input,number,output,startTime,status,updateTime\", \"gerritChanges\": [{\"change\": \"123456\", \"host\": \"flutter-review.googlesource.com\", \"patchset\": \"7\", \"project\": \"mirrors/engine\"}], \"gitilesCommit\": {\"host\": \"flutter.googlesource.com\", \"id\": \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\", \"project\": \"mirrors/engine\", \"ref\": \"refs/heads/main\"}, \"priority\": 30, \"properties\": {\"$flutter/osx_sdk\": {\"sdk_version\": \"14a5294e\"}, \"build\": {\"drone_dimensions\": [\"os=Linux\"], \"name\": \"linux one\", \"properties\": {\"$flutter/osx_sdk\": {\"sdk_version\": \"14a5294e\"}, \"release_build\": true}, \"recipe\": \"engine/something\"}, \"build_identifier\": \"8945511751514863184\", \"environment\": \"Staging\", \"gclient_variables\": {}, \"parent_commit\": \"\", \"recipe\": \"engine/something\", \"release_build\": true, \"repository\": \"engine\"}, \"requestId\": \"8945511751514863184-00000000-0000-0000-0000-000000001337\", \"swarming\": {\"parentRunId\": \"fake-task-id\"}, \"tags\": [{\"key\": \"cq_experimental\", \"value\": \"false\"}, {\"key\": \"parent_buildbucket_id\", \"value\": \"8945511751514863184\"}, {\"key\": \"user_agent\", \"value\": \"recipe\"}]}}]}",
+    "stdin": "{\"requests\": [{\"scheduleBuild\": {\"builder\": {\"bucket\": \"try\", \"builder\": \"Linux Engine Drone\", \"project\": \"prod\"}, \"dimensions\": [{\"key\": \"os\", \"value\": \"Linux\"}], \"exe\": {\"cipdVersion\": \"refs/heads/main\"}, \"experimental\": \"NO\", \"experiments\": {\"luci.buildbucket.parent_tracking\": false}, \"fields\": \"builder,createTime,createdBy,critical,endTime,id,infra,input,number,output,startTime,status,updateTime\", \"gerritChanges\": [{\"change\": \"123456\", \"host\": \"flutter-review.googlesource.com\", \"patchset\": \"7\", \"project\": \"mirrors/engine\"}], \"gitilesCommit\": {\"host\": \"flutter.googlesource.com\", \"id\": \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\", \"project\": \"mirrors/engine\", \"ref\": \"refs/heads/main\"}, \"priority\": 30, \"properties\": {\"$flutter/osx_sdk\": {\"sdk_version\": \"14a5294e\"}, \"build\": {\"drone_dimensions\": [\"os=Linux\"], \"name\": \"linux one\", \"properties\": {\"$flutter/osx_sdk\": {\"sdk_version\": \"14a5294e\"}, \"release_build\": \"true\"}, \"recipe\": \"engine/something\"}, \"build_identifier\": \"8945511751514863184\", \"environment\": \"Staging\", \"gclient_variables\": {}, \"parent_commit\": \"\", \"recipe\": \"engine/something\", \"release_build\": \"true\", \"repository\": \"engine\"}, \"requestId\": \"8945511751514863184-00000000-0000-0000-0000-000000001337\", \"swarming\": {\"parentRunId\": \"fake-task-id\"}, \"tags\": [{\"key\": \"cq_experimental\", \"value\": \"false\"}, {\"key\": \"parent_buildbucket_id\", \"value\": \"8945511751514863184\"}, {\"key\": \"user_agent\", \"value\": \"recipe\"}]}}]}",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -472,7 +472,7 @@
       "@@@STEP_LOG_LINE@request@              \"$flutter/osx_sdk\": {@@@",
       "@@@STEP_LOG_LINE@request@                \"sdk_version\": \"14a5294e\"@@@",
       "@@@STEP_LOG_LINE@request@              },@@@",
-      "@@@STEP_LOG_LINE@request@              \"release_build\": true@@@",
+      "@@@STEP_LOG_LINE@request@              \"release_build\": \"true\"@@@",
       "@@@STEP_LOG_LINE@request@            },@@@",
       "@@@STEP_LOG_LINE@request@            \"recipe\": \"engine/something\"@@@",
       "@@@STEP_LOG_LINE@request@          },@@@",
@@ -481,7 +481,7 @@
       "@@@STEP_LOG_LINE@request@          \"gclient_variables\": {},@@@",
       "@@@STEP_LOG_LINE@request@          \"parent_commit\": \"\",@@@",
       "@@@STEP_LOG_LINE@request@          \"recipe\": \"engine/something\",@@@",
-      "@@@STEP_LOG_LINE@request@          \"release_build\": true,@@@",
+      "@@@STEP_LOG_LINE@request@          \"release_build\": \"true\",@@@",
       "@@@STEP_LOG_LINE@request@          \"repository\": \"engine\"@@@",
       "@@@STEP_LOG_LINE@request@        },@@@",
       "@@@STEP_LOG_LINE@request@        \"requestId\": \"8945511751514863184-00000000-0000-0000-0000-000000001337\",@@@",
diff --git a/recipes/release/release_builder.expected/base_linux_main_monorepo.json b/recipes/release/release_builder.expected/base_linux_main_monorepo.json
index 9e487c3..43db4a6 100644
--- a/recipes/release/release_builder.expected/base_linux_main_monorepo.json
+++ b/recipes/release/release_builder.expected/base_linux_main_monorepo.json
@@ -290,7 +290,7 @@
       "@@@STEP_LOG_LINE@json.output@      \"name\": \"linux one\",@@@",
       "@@@STEP_LOG_LINE@json.output@      \"properties\": {@@@",
       "@@@STEP_LOG_LINE@json.output@        \"$flutter/osx_sdk\": \"{\\\"sdk_version\\\": \\\"14a5294e\\\"}\",@@@",
-      "@@@STEP_LOG_LINE@json.output@        \"release_build\": true@@@",
+      "@@@STEP_LOG_LINE@json.output@        \"release_build\": \"true\"@@@",
       "@@@STEP_LOG_LINE@json.output@      },@@@",
       "@@@STEP_LOG_LINE@json.output@      \"recipe\": \"engine/something\"@@@",
       "@@@STEP_LOG_LINE@json.output@    },@@@",
@@ -403,7 +403,7 @@
       }
     },
     "name": "launch builds.schedule",
-    "stdin": "{\"requests\": [{\"scheduleBuild\": {\"builder\": {\"bucket\": \"try\", \"builder\": \"Linux Engine Drone\", \"project\": \"prod\"}, \"dimensions\": [{\"key\": \"os\", \"value\": \"Linux\"}], \"exe\": {\"cipdVersion\": \"refs/heads/main\"}, \"experimental\": \"NO\", \"experiments\": {\"luci.buildbucket.parent_tracking\": false}, \"fields\": \"builder,createTime,createdBy,critical,endTime,id,infra,input,number,output,startTime,status,updateTime\", \"gerritChanges\": [{\"change\": \"123456\", \"host\": \"flutter-review.googlesource.com\", \"patchset\": \"7\", \"project\": \"mirrors/engine\"}], \"gitilesCommit\": {\"host\": \"flutter.googlesource.com\", \"id\": \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\", \"project\": \"mirrors/engine\", \"ref\": \"refs/heads/main\"}, \"priority\": 30, \"properties\": {\"$flutter/osx_sdk\": {\"sdk_version\": \"14a5294e\"}, \"build\": {\"drone_dimensions\": [\"os=Linux\"], \"name\": \"linux one\", \"properties\": {\"$flutter/osx_sdk\": {\"sdk_version\": \"14a5294e\"}, \"release_build\": true}, \"recipe\": \"engine/something\"}, \"build_identifier\": \"8945511751514863184\", \"environment\": \"Staging\", \"gclient_variables\": {}, \"parent_commit\": \"\", \"recipe\": \"engine/something\", \"release_build\": true, \"repository\": \"engine\"}, \"requestId\": \"8945511751514863184-00000000-0000-0000-0000-000000001337\", \"swarming\": {\"parentRunId\": \"fake-task-id\"}, \"tags\": [{\"key\": \"cq_experimental\", \"value\": \"false\"}, {\"key\": \"parent_buildbucket_id\", \"value\": \"8945511751514863184\"}, {\"key\": \"user_agent\", \"value\": \"recipe\"}]}}]}",
+    "stdin": "{\"requests\": [{\"scheduleBuild\": {\"builder\": {\"bucket\": \"try\", \"builder\": \"Linux Engine Drone\", \"project\": \"prod\"}, \"dimensions\": [{\"key\": \"os\", \"value\": \"Linux\"}], \"exe\": {\"cipdVersion\": \"refs/heads/main\"}, \"experimental\": \"NO\", \"experiments\": {\"luci.buildbucket.parent_tracking\": false}, \"fields\": \"builder,createTime,createdBy,critical,endTime,id,infra,input,number,output,startTime,status,updateTime\", \"gerritChanges\": [{\"change\": \"123456\", \"host\": \"flutter-review.googlesource.com\", \"patchset\": \"7\", \"project\": \"mirrors/engine\"}], \"gitilesCommit\": {\"host\": \"flutter.googlesource.com\", \"id\": \"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\", \"project\": \"mirrors/engine\", \"ref\": \"refs/heads/main\"}, \"priority\": 30, \"properties\": {\"$flutter/osx_sdk\": {\"sdk_version\": \"14a5294e\"}, \"build\": {\"drone_dimensions\": [\"os=Linux\"], \"name\": \"linux one\", \"properties\": {\"$flutter/osx_sdk\": {\"sdk_version\": \"14a5294e\"}, \"release_build\": \"true\"}, \"recipe\": \"engine/something\"}, \"build_identifier\": \"8945511751514863184\", \"environment\": \"Staging\", \"gclient_variables\": {}, \"parent_commit\": \"\", \"recipe\": \"engine/something\", \"release_build\": \"true\", \"repository\": \"engine\"}, \"requestId\": \"8945511751514863184-00000000-0000-0000-0000-000000001337\", \"swarming\": {\"parentRunId\": \"fake-task-id\"}, \"tags\": [{\"key\": \"cq_experimental\", \"value\": \"false\"}, {\"key\": \"parent_buildbucket_id\", \"value\": \"8945511751514863184\"}, {\"key\": \"user_agent\", \"value\": \"recipe\"}]}}]}",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -472,7 +472,7 @@
       "@@@STEP_LOG_LINE@request@              \"$flutter/osx_sdk\": {@@@",
       "@@@STEP_LOG_LINE@request@                \"sdk_version\": \"14a5294e\"@@@",
       "@@@STEP_LOG_LINE@request@              },@@@",
-      "@@@STEP_LOG_LINE@request@              \"release_build\": true@@@",
+      "@@@STEP_LOG_LINE@request@              \"release_build\": \"true\"@@@",
       "@@@STEP_LOG_LINE@request@            },@@@",
       "@@@STEP_LOG_LINE@request@            \"recipe\": \"engine/something\"@@@",
       "@@@STEP_LOG_LINE@request@          },@@@",
@@ -481,7 +481,7 @@
       "@@@STEP_LOG_LINE@request@          \"gclient_variables\": {},@@@",
       "@@@STEP_LOG_LINE@request@          \"parent_commit\": \"\",@@@",
       "@@@STEP_LOG_LINE@request@          \"recipe\": \"engine/something\",@@@",
-      "@@@STEP_LOG_LINE@request@          \"release_build\": true,@@@",
+      "@@@STEP_LOG_LINE@request@          \"release_build\": \"true\",@@@",
       "@@@STEP_LOG_LINE@request@          \"repository\": \"engine\"@@@",
       "@@@STEP_LOG_LINE@request@        },@@@",
       "@@@STEP_LOG_LINE@request@        \"requestId\": \"8945511751514863184-00000000-0000-0000-0000-000000001337\",@@@",
diff --git a/recipes/release/release_builder.py b/recipes/release/release_builder.py
index ff77b35..aa0741f 100644
--- a/recipes/release/release_builder.py
+++ b/recipes/release/release_builder.py
@@ -69,7 +69,7 @@
       # Current branch didn't match any of the enabled branches.
       return False
 
-  release_build = target.get('properties', {}).get('release_build', False)
+  release_build = target.get('properties', {}).get('release_build', '') == 'true'
   for_this_platform = target['name'].lower().startswith(api.platform.name)
   # Postsubmit for engine and flutter repositories.
   # TODO(fujino): once 3.29 reaches stable, ignore repo_context
@@ -211,7 +211,7 @@
   tasks_dict = {
       'targets': [{
           'name': 'linux one', 'recipe': 'engine/something', 'properties': {
-              'release_build': True,
+              'release_build': 'true',
               '$flutter/osx_sdk': '{"sdk_version": "14a5294e"}'
           }, 'drone_dimensions': ['os=Linux']
       }, {