GitHub Release for Android using Actions.

build.yml

name: Android Build

on:
  workflow_dispatch:
#  push:
#    branches:
#      - 'floss'
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      # 1
      - name: Checkout code
        uses: actions/checkout@v2
      # 2
      - name: Generate Release APK
        run: ./gradlew assembleFossRelease
      # 3
      - name: Sign APK
        uses: r0adkll/sign-android-release@v1
        # ID used to access action output
        id: sign_app
        with:
          releaseDirectory: app/build/outputs/apk/foss/release
          signingKeyBase64: ${{ secrets.SIGNING_KEY }}
          alias: ${{ secrets.ALIAS }}
          keyStorePassword: ${{ secrets.KEY_STORE_PASSWORD }}
          keyPassword: ${{ secrets.KEY_PASSWORD }}
      # 4
      - uses: actions/upload-artifact@master
        with:
          name: release.apk
          path: ${{steps.sign_app.outputs.signedReleaseFile}}
      # 5
      - uses: actions/upload-artifact@master
        with:
          name: mapping.txt
          path: app/build/outputs/mapping/release/mapping.txt

release.yml

name: Github Publish

on:
  workflow_dispatch:
#  push:
#    branches:
#      - 'floss'
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      # 1
      - uses: dawidd6/action-download-artifact@v2
        with:
          github_token: ${{secrets.GITHUB_TOKEN}}
          workflow: build.yml
          workflow_conclusion: success
          branch: floss
          name: release.apk
          path: downloads
          if_no_artifact_found: fail
      # 2
      - name: Generate release tag
        id: tag
        run: |
          echo "::set-output name=release_tag::APP_$(date +"%Y.%m.%d_%H-%M")"
      # 3
      - name: Release
        uses: softprops/action-gh-release@v1
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        with:
          tag_name: ${{ steps.tag.outputs.release_tag }}
          files: downloads/release-signed.apk