Build flutter releases in github actions for production only android for while.

flutter-android-cd.yml

# This is a basic workflow to help you get started with Actions
name: CD

# Controls when the action will run. Triggers the workflow on push or pull request
# events but only for the master branch
on:
  push:
    tags:
      - "v*.*.*" # on every version tag will build a new android artifact.
jobs:
  build:
    name: Build APK
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v1
      - name: Setup Java
        uses: actions/setup-java@v1
        with:
          java-version: "12.x"
      - name: Setup Flutter
        uses: subosito/flutter-action@v1
        with:
          flutter-version: "1.17.5"

      - name: Decoding android/key.properties
        run: echo "${{ secrets.KEYPROP_PROD }}" | base64 --decode > android/key.properties

      - name: Decoding android/neumodore_key.jks
        run: echo "${{ secrets.KEYJKS_PROD }}" | base64 --decode > android/key.jks

      - name: Pub Get Packages
        run: flutter pub get

      - name: Build APK
        run: flutter build apk --split-per-abi --release

      - name: Build APPBUNDLE
        run: flutter build appbundle --release

      - name: Create Github Release
        uses: ncipollo/release-action@v1
        with:
          artifacts: "build/app/outputs/apk/release/*.apk,build/app/outputs/bundle/release/*.aab"
          token: ${{ secrets.RELEASES_TOKEN }}