[cortinico]

Summary

Replace the obsolete GitHub Actions Buck job with a Gradle build of the SoLoader
Android AAR and the separate annotation and nativeloader JARs. Add Maven Local
publications for all three artifacts and check them in CI. Keep the Buck files
available, but do not run them in GitHub Actions. This does not publish to Maven
Central.

The publication version is read from the existing artifact configurations.
The Java 7 class-file target and the library manifest metadata preserve the
compatibility of the existing Maven artifacts.

Test plan

• git -c core.whitespace=cr-at-eol diff --cached --check passed (the generated Windows wrapper uses CRLF).
• ./gradlew publishToMavenLocal passed locally on JDK 17 with JVM proxy settings, publishing to a temporary Maven Local repository.
• Compared local 0.13.0 publications against Maven Central 0.12.1: AAR/JAR formats, three source and Javadoc JAR pairs, POM coordinates and dependency scopes, and Java 7 class-file versions match. Sources differ between the versions, so binary equality is not expected.
• Maven Central does not have 0.13.1 (the version requested for comparison); the 0.13.1 POM returns 404.
• CI passed with the Maven Local publishing step.

The new AAR does not preserve the obsolete targetSdkVersion=23 entry from the
Buck-generated manifest: the Android Gradle Plugin omits library target SDKs.
Its minSdkVersion=9 and SoLoader application metadata are preserved. The
stale manifest versionName=0.1.0 and versionCode=1 are intentionally omitted;
the Maven publication version comes from the artifact configurations.

[meta-codesync]

@cortinico has imported this pull request. If you are a Meta employee, you can view this in D128666153.