Add GitHub workflow action for Android build

[Copilot]

Adds CI workflow to build Android example applications on push/PR to main.

Changes

• New workflow: .github/workflows/android-build.yml
  • Matrix build for LlamaDemo and DeepLabV3Demo projects
  • JDK 17 (Temurin) + Gradle setup with caching
  • APK artifact upload per project
  • Explicit permissions: contents: read for security

Scope

Only projects using Maven dependencies are included. Projects requiring local AAR files (Yolo, Whisper, CIFAR) need a separate workflow to first build/download ExecutorTorch artifacts.

Original prompt

Help me add a github workflow action for android build

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[kirklandsign]

@copilot does ubuntu-latest come with jdk already?

[Copilot]

@copilot does ubuntu-latest come with jdk already?

Yes, ubuntu-latest comes with JDK 8, 11, 17 (default), 21, and 25 pre-installed. The setup-java action is still useful for: ensuring a consistent version across runs, setting up Gradle dependency caching, and guaranteeing the Temurin distribution. That said, if you'd prefer to rely on the pre-installed JDK and remove this step, I can do that.

[kirklandsign]

@copilot For actions/upload-artifact@v4, does it upload to a github s3? what quota or pricing is it

[Copilot]

@copilot For actions/upload-artifact@v4, does it upload to a github s3? what quota or pricing is it

Artifacts are stored in GitHub's own storage (Azure-backed), not a separate S3 bucket. For public repos, artifact storage is free with unlimited storage. Artifacts have a default 90-day retention (configurable). For private repos, storage counts against your account's included storage quota (varies by plan), with overage at $0.25/GB/month. If you'd prefer to skip the artifact upload step to avoid any concerns, I can remove it.

[kirklandsign]

@copilot is it possible to upload it the apk to google play store?

[Copilot]

@copilot is it possible to upload it the apk to google play store?

Yes, it's possible using the r0adkll/upload-google-play action. It requires: (1) a Google Play service account JSON key stored as a GitHub secret, (2) signing the APK/AAB with a release keystore, and (3) the app already registered in Google Play Console. Would you like me to add this as a separate deployment workflow? Note that demo/example apps typically aren't published to Play Store, so this may be better suited for production apps.

[psiddh]

Nice!!

[kirklandsign]

@copilot make a new PR to make it nightly instead of per push or pull request