Add GitHub Actions workflow to build and publish Android release APK

[dusy4]

Motivation

• Add CI to build the Android release APK and attach it to GitHub Releases automatically for tagged releases.
• Allow manual release runs via workflow_dispatch with an optional release_tag and ensure a tag is created for manual runs.

Description

• Add .github/workflows/android-release.yml defining a build_apk job that checks out the repo, sets up JDK 17 and Gradle, runs ./gradlew --no-daemon assembleRelease, and uploads android/app/build/outputs/apk/release/app-release.apk as the app-release-apk artifact.
• Add a publish_release job that runs for tag refs matching v* or when workflow_dispatch includes release_tag, resolves RELEASE_TAG, creates and pushes the tag for manual runs, downloads the APK artifact, and attaches it to the GitHub Release using softprops/action-gh-release@v2.
• Set workflow permissions to contents: write and use standard actions actions/checkout@v4, actions/setup-java@v4, gradle/actions/setup-gradle@v4, actions/upload-artifact@v4, and actions/download-artifact@v4.

Testing

• No automated unit or integration tests were added or executed as part of this change.
• The new workflow is configured to run on pushes to main, on tag pushes matching v*, and via workflow_dispatch for future verification.

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Codex Task