Rename maven to protobuf_maven in MODULE.bazel (#18641) (#19477)

The default name for the rules_jvm_external.maven rule is "maven". When not set, it defaults to "maven". For root modules also using rules_jvm_external, the name clash causes a warning:

```
DEBUG: $TMP/external/rules_jvm_external~/private/extensions/maven.bzl:154:14:
The maven repository 'maven' is used in two different bazel modules,
originally in '<my_workspace>' and now in 'protobuf'
```

Summarizing @shs96c in [1]:

> The common maven repo name allows rulesets to contribute to the user's JARs.
> However, this implies that maven is for the end user, not for transitive
> dependencies. If a ruleset needs private dependencies, it should use a custom
> namespace rather than the maven namespace.

Since protobuf is not contributing to user's JARs, we'll use a custom namespace. There's precedent for using a custom namespace for library modules:

- rules_jvm_external uses `rules_jvm_external_deps` instead of `maven`.
- rules_kotlin uses `kotlin_rules_maven` instead of `maven`.

[1]: https://github.com/bazel-contrib/rules_jvm_external/issues/916#issuecomment-1645527584

Fixes #16839.

Closes #18641

COPYBARA_INTEGRATE_REVIEW=https://github.com/protocolbuffers/protobuf/pull/18641 from jschaf:joe/protobuf-maven bd2c62f3118264adc1e725102d1ecc576f145f35
PiperOrigin-RevId: 684625084

Co-authored-by: Joe Schafer <joe.schafer@delta46.us>
diff --git a/MODULE.bazel b/MODULE.bazel
index 4f4fa0f..a9a93ca 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -131,6 +131,7 @@
 maven = use_extension("@rules_jvm_external//:extensions.bzl", "maven")
 
 maven.install(
+    name = "protobuf_maven",
     artifacts = [
         "com.google.caliper:caliper:1.0-beta-3",
         "com.google.code.findbugs:jsr305:3.0.2",
@@ -151,7 +152,7 @@
     ],
 )
 
-use_repo(maven, "maven")
+use_repo(maven, "protobuf_maven")
 
 # Development dependencies
 bazel_dep(
diff --git a/WORKSPACE b/WORKSPACE
index dda7d44..1652c79 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -59,6 +59,7 @@
 load("@rules_jvm_external//:defs.bzl", "maven_install")
 
 maven_install(
+    name = "protobuf_maven",
     artifacts = PROTOBUF_MAVEN_ARTIFACTS,
     # For updating instructions, see:
     # https://github.com/bazelbuild/rules_jvm_external#updating-maven_installjson
@@ -69,7 +70,7 @@
     ],
 )
 
-load("@maven//:defs.bzl", "pinned_maven_install")
+load("@protobuf_maven//:defs.bzl", "pinned_maven_install")
 
 pinned_maven_install()
 
diff --git a/java/core/BUILD.bazel b/java/core/BUILD.bazel
index 63b5f4a..2d6cf2f 100644
--- a/java/core/BUILD.bazel
+++ b/java/core/BUILD.bazel
@@ -391,8 +391,8 @@
         ":generic_test_protos_java_proto",
         ":java_test_protos_java_proto",
         ":lite_test_protos_java_proto",
-        "@maven//:com_google_guava_guava",
-        "@maven//:junit_junit",
+        "@protobuf_maven//:com_google_guava_guava",
+        "@protobuf_maven//:junit_junit",
     ],
 )
 
@@ -442,10 +442,10 @@
         ":java_test_protos_java_proto",
         ":lite_test_protos_java_proto",
         ":test_util",
-        "@maven//:com_google_guava_guava",
-        "@maven//:com_google_truth_truth",
-        "@maven//:junit_junit",
-        "@maven//:org_mockito_mockito_core",
+        "@protobuf_maven//:com_google_guava_guava",
+        "@protobuf_maven//:com_google_truth_truth",
+        "@protobuf_maven//:junit_junit",
+        "@protobuf_maven//:org_mockito_mockito_core",
     ],
 )
 
@@ -461,9 +461,9 @@
     ],
     deps = [
         ":core",
-        "@maven//:com_google_guava_guava",
-        "@maven//:com_google_truth_truth",
-        "@maven//:junit_junit",
+        "@protobuf_maven//:com_google_guava_guava",
+        "@protobuf_maven//:com_google_truth_truth",
+        "@protobuf_maven//:junit_junit",
     ],
 )
 
@@ -518,8 +518,8 @@
         ":java_test_protos_java_proto_lite",
         ":lite_runtime_only",
         ":lite_test_protos_java_proto_lite",
-        "@maven//:com_google_guava_guava",
-        "@maven//:junit_junit",
+        "@protobuf_maven//:com_google_guava_guava",
+        "@protobuf_maven//:junit_junit",
     ],
 )
 
@@ -586,9 +586,9 @@
         ":lite",
         ":lite_test_protos_java_proto_lite",
         ":test_util_lite",
-        "@maven//:com_google_truth_truth",
-        "@maven//:junit_junit",
-        "@maven//:org_mockito_mockito_core",
+        "@protobuf_maven//:com_google_truth_truth",
+        "@protobuf_maven//:junit_junit",
+        "@protobuf_maven//:org_mockito_mockito_core",
     ],
 )
 
@@ -602,8 +602,8 @@
     deps = [
         ":core",
         "//compatibility:v25_test_protos_srcjar",
-        "@maven//:com_google_guava_guava",
-        "@maven//:junit_junit",
+        "@protobuf_maven//:com_google_guava_guava",
+        "@protobuf_maven//:junit_junit",
     ],
 )
 
@@ -634,10 +634,10 @@
         ":core",
         ":v25_test_util_srcjar",
         "//compatibility:v25_test_protos_srcjar",
-        "@maven//:com_google_guava_guava",
-        "@maven//:com_google_truth_truth",
-        "@maven//:junit_junit",
-        "@maven//:org_mockito_mockito_core",
+        "@protobuf_maven//:com_google_guava_guava",
+        "@protobuf_maven//:com_google_truth_truth",
+        "@protobuf_maven//:junit_junit",
+        "@protobuf_maven//:org_mockito_mockito_core",
     ],
 )
 
@@ -651,8 +651,8 @@
     deps = [
         ":core",
         "//compatibility:v25_test_protos_jar",
-        "@maven//:com_google_guava_guava",
-        "@maven//:junit_junit",
+        "@protobuf_maven//:com_google_guava_guava",
+        "@protobuf_maven//:junit_junit",
     ],
 )
 
@@ -683,10 +683,10 @@
         ":core",
         ":v25_test_util_jar",
         "//compatibility:v25_test_protos_jar",
-        "@maven//:com_google_guava_guava",
-        "@maven//:com_google_truth_truth",
-        "@maven//:junit_junit",
-        "@maven//:org_mockito_mockito_core",
+        "@protobuf_maven//:com_google_guava_guava",
+        "@protobuf_maven//:com_google_truth_truth",
+        "@protobuf_maven//:junit_junit",
+        "@protobuf_maven//:org_mockito_mockito_core",
     ],
 )
 
diff --git a/java/internal/BUILD.bazel b/java/internal/BUILD.bazel
index 96958e9..4133605 100644
--- a/java/internal/BUILD.bazel
+++ b/java/internal/BUILD.bazel
@@ -18,7 +18,7 @@
     srcs = ["JavaVersionTest.java"],
     test_class = "JavaVersionTest",
     deps = [
-        "@maven//:com_google_truth_truth",
-        "@maven//:junit_junit",
+        "@protobuf_maven//:com_google_truth_truth",
+        "@protobuf_maven//:junit_junit",
     ],
 )
diff --git a/java/kotlin-lite/BUILD.bazel b/java/kotlin-lite/BUILD.bazel
index 493ba1a..8570268 100644
--- a/java/kotlin-lite/BUILD.bazel
+++ b/java/kotlin-lite/BUILD.bazel
@@ -114,8 +114,8 @@
         "//java/kotlin:only_for_use_in_proto_generated_code_its_generator_and_tests",
         "//java/kotlin:shared_runtime",
         "//java/lite",
-        "@maven//:com_google_truth_truth",
-        "@maven//:junit_junit",
+        "@protobuf_maven//:com_google_truth_truth",
+        "@protobuf_maven//:junit_junit",
         "@rules_kotlin//kotlin/compiler:kotlin-test",
     ],
 )
@@ -210,8 +210,8 @@
     deps = [
         ":kotlin_unittest_lite",
         "//java/core:test_util_lite",
-        "@maven//:com_google_truth_truth",
-        "@maven//:junit_junit",
+        "@protobuf_maven//:com_google_truth_truth",
+        "@protobuf_maven//:junit_junit",
     ],
 )
 
@@ -227,8 +227,8 @@
     deps = [
         ":kotlin_proto3_unittest_lite",
         "//java/core:test_util_lite",
-        "@maven//:com_google_truth_truth",
-        "@maven//:junit_junit",
+        "@protobuf_maven//:com_google_truth_truth",
+        "@protobuf_maven//:junit_junit",
     ],
 )
 
diff --git a/java/kotlin/BUILD.bazel b/java/kotlin/BUILD.bazel
index d0fe25f..1d9cb5f 100644
--- a/java/kotlin/BUILD.bazel
+++ b/java/kotlin/BUILD.bazel
@@ -116,8 +116,8 @@
     deps = [
         ":bytestring_lib",
         "//java/lite",
-        "@maven//:com_google_truth_truth",
-        "@maven//:junit_junit",
+        "@protobuf_maven//:com_google_truth_truth",
+        "@protobuf_maven//:junit_junit",
         "@rules_kotlin//kotlin/compiler:kotlin-test",
     ],
 )
@@ -151,9 +151,9 @@
         ":example_extensible_message_java_proto",
         ":only_for_use_in_proto_generated_code_its_generator_and_tests",
         ":shared_runtime",
-        "@maven//:com_google_guava_guava_testlib",
-        "@maven//:com_google_truth_truth",
-        "@maven//:junit_junit",
+        "@protobuf_maven//:com_google_guava_guava_testlib",
+        "@protobuf_maven//:com_google_truth_truth",
+        "@protobuf_maven//:junit_junit",
         "@rules_kotlin//kotlin/compiler:kotlin-test",
     ],
 )
@@ -177,8 +177,8 @@
         ":only_for_use_in_proto_generated_code_its_generator_and_tests",
         ":shared_runtime",
         "//java/core",
-        "@maven//:com_google_truth_truth",
-        "@maven//:junit_junit",
+        "@protobuf_maven//:com_google_truth_truth",
+        "@protobuf_maven//:junit_junit",
         "@rules_kotlin//kotlin/compiler:kotlin-test",
     ],
 )
@@ -289,8 +289,8 @@
     deps = [
         ":kotlin_unittest",
         "//java/core:test_util",
-        "@maven//:com_google_truth_truth",
-        "@maven//:junit_junit",
+        "@protobuf_maven//:com_google_truth_truth",
+        "@protobuf_maven//:junit_junit",
         "@rules_kotlin//kotlin/compiler:kotlin-reflect",
     ],
 )
@@ -307,8 +307,8 @@
     deps = [
         ":kotlin_proto3_unittest",
         "//java/core:test_util",
-        "@maven//:com_google_truth_truth",
-        "@maven//:junit_junit",
+        "@protobuf_maven//:com_google_truth_truth",
+        "@protobuf_maven//:junit_junit",
     ],
 )
 
diff --git a/java/lite/BUILD.bazel b/java/lite/BUILD.bazel
index f19cc38..b4df648 100644
--- a/java/lite/BUILD.bazel
+++ b/java/lite/BUILD.bazel
@@ -76,8 +76,8 @@
         "//java/core:java_test_protos_java_proto_lite",
         "//java/core:lite_test_protos_java_proto_lite",
         "//java/core:test_util_lite",
-        "@maven//:com_google_truth_truth",
-        "@maven//:junit_junit",
+        "@protobuf_maven//:com_google_truth_truth",
+        "@protobuf_maven//:junit_junit",
     ],
 )
 
diff --git a/java/osgi/BUILD.bazel b/java/osgi/BUILD.bazel
index 223e6fe..0a9b210 100644
--- a/java/osgi/BUILD.bazel
+++ b/java/osgi/BUILD.bazel
@@ -9,8 +9,8 @@
     srcs = ["OsgiWrapper.java"],
     main_class = "com.google.protobuf.osgi.OsgiWrapper",
     deps = [
-        "@maven//:biz_aQute_bnd_biz_aQute_bndlib",
-        "@maven//:com_google_guava_guava",
-        "@maven//:info_picocli_picocli",
+        "@protobuf_maven//:biz_aQute_bnd_biz_aQute_bndlib",
+        "@protobuf_maven//:com_google_guava_guava",
+        "@protobuf_maven//:info_picocli_picocli",
     ],
 )
diff --git a/java/util/BUILD.bazel b/java/util/BUILD.bazel
index 271bee1..c6ad3e5 100644
--- a/java/util/BUILD.bazel
+++ b/java/util/BUILD.bazel
@@ -13,11 +13,11 @@
     visibility = ["//visibility:public"],
     deps = [
         "//java/core",
-        "@maven//:com_google_code_findbugs_jsr305",
-        "@maven//:com_google_code_gson_gson",
-        "@maven//:com_google_errorprone_error_prone_annotations",
-        "@maven//:com_google_guava_guava",
-        "@maven//:com_google_j2objc_j2objc_annotations",
+        "@protobuf_maven//:com_google_code_findbugs_jsr305",
+        "@protobuf_maven//:com_google_code_gson_gson",
+        "@protobuf_maven//:com_google_errorprone_error_prone_annotations",
+        "@protobuf_maven//:com_google_guava_guava",
+        "@protobuf_maven//:com_google_j2objc_j2objc_annotations",
     ],
 )
 
@@ -33,11 +33,11 @@
     visibility = ["//visibility:public"],
     deps = [
         "//java/core",
-        "@maven//:com_google_code_findbugs_jsr305",
-        "@maven//:com_google_code_gson_gson",
-        "@maven//:com_google_errorprone_error_prone_annotations",
-        "@maven//:com_google_guava_guava",
-        "@maven//:com_google_j2objc_j2objc_annotations",
+        "@protobuf_maven//:com_google_code_findbugs_jsr305",
+        "@protobuf_maven//:com_google_code_gson_gson",
+        "@protobuf_maven//:com_google_errorprone_error_prone_annotations",
+        "@protobuf_maven//:com_google_guava_guava",
+        "@protobuf_maven//:com_google_j2objc_j2objc_annotations",
     ],
 )
 
@@ -90,10 +90,10 @@
         ":util",
         "//java/core",
         "//java/core:generic_test_protos_java_proto",
-        "@maven//:com_google_code_gson_gson",
-        "@maven//:com_google_guava_guava",
-        "@maven//:com_google_truth_truth",
-        "@maven//:junit_junit",
+        "@protobuf_maven//:com_google_code_gson_gson",
+        "@protobuf_maven//:com_google_guava_guava",
+        "@protobuf_maven//:com_google_truth_truth",
+        "@protobuf_maven//:junit_junit",
     ],
 )