Add GitHub Actions workflow to build and publish Android release APK

[dusy4]

Motivation

• Add CI to build Android release APKs and provide an automated path to publish the APK to a GitHub release when creating a v* tag or via manual dispatch.

Description

• Introduce a new workflow file /.github/workflows/android-release.yml that triggers on pushes to main, tags matching v*, pull requests to main, and workflow_dispatch with an optional release_tag input.
• Add build-apk job which sets up JDK 17 and Gradle then runs ./gradlew --no-daemon assembleRelease in the android directory and uploads the built app-release.apk as an artifact.
• Add publish-release job that runs after build and conditionally publishes when the ref is a v* tag or a workflow_dispatch with release_tag, resolves or creates the release tag, downloads the artifact, and attaches the APK to a GitHub release using softprops/action-gh-release@v2.

Testing

• No automated tests were executed as part of this PR; the new workflow will run on the configured triggers once merged and can be validated by observing the GitHub Actions run results after a push or tag.

---

Codex Task