ci: set guice_custom_class_loading=OFF in unmanaged-dependency-check

[blakeli0]

Motivation

GitHub Actions ubuntu-22.04 runners recently upgraded pre-installed Maven from 3.9.16 to 3.10.0, which sets the JVM system property -Dguice_custom_class_loading=CHILD when starting Maven and routes java.util.logging output to stdout during exec:java.

Because unmanaged-dependency-check depends on com.google.cloud.tools:dependencies:1.5.13 (which pulls in com.google.inject:guice:4.2.1), running mvn exec:java logs a Guice warning (WARNING: CHILD is not a valid flag value for guice_custom_class_loading. Values must be one of [OFF, BRIDGE]) before printing [], causing sdk-platform-java Downstream Unmanaged Dependency Check to fail when comparing stdout against "[]".

Modifications

• Configure guice_custom_class_loading=OFF in exec-maven-plugin <systemProperties> inside sdk-platform-java/java-shared-dependencies/unmanaged-dependency-check/pom.xml.

[gemini-code-assist]

Code Review

This pull request updates the Maven configuration in pom.xml for the unmanaged-dependency-check tool, adding a system property guice_custom_class_loading set to OFF during execution. There are no review comments, and the changes are straightforward with no further feedback to provide.

[lqiu96]

LGTM

Two general questions (not blocking this PR specifically and can be looked at in the future):

1. What is the unmanaged dependency check doing again? I don't recall this one and I wonder if this is one of those CIs that falls under the "needed in split repos but maybe not for the monorepo"
2. Would it be possible to just upgrade/ override guice version instead? I think I would prefer to not have random configs unless there isn't any other option