Github action for android deployment using flutter

android_deployment.yml

name: Flutter CD - Deployment Android

on:
  push:
    branches:
      - "main"
  pull_request:
    branches:
      - "main"

jobs:
    flutter_build_android:
        name: Build Android APK
        runs-on: ubuntu-latest
        steps:
            - name: Checkout the branch
              uses: actions/checkout@v4

            - name: Setup Flutter SDK
              uses: subosito/flutter-action@v2
              with:
                  channel: 'stable'
                  cache: true

            - name: Cache Pub Dependencies
              uses: actions/cache@v3
              with:
                path: ~/.pub-cache
                key: ${{ runner.os }}-pub-${{ hashFiles('pubspec.lock') }}
                restore-keys: |
                  ${{ runner.os }}-pub-
            
            - name: Get packages
              run: flutter pub get

            - name: Decode Keystore
              env:
                ENCODED_STRING: ${{ secrets.encodedStoreFile }}
              run: |
                      echo $ENCODED_STRING > keystore-b64.txt
                      base64 -d keystore-b64.txt > keystore.jks

            - name: Build Release APK
              env:
                storePassword: ${{ secrets.storePassword }}
                keyAlias: ${{ secrets.keyAlias }}
                keyPassword: ${{ secrets.keyPassword }} 
              run: flutter build apk --flavor YOUR_FLAVOR --obfuscate --split-debug-info=YOUR_PATH

            - name: Build Release AppBundle
              env:
                storePassword: ${{ secrets.storePassword }}
                keyAlias: ${{ secrets.keyAlias }}
                keyPassword: ${{ secrets.keyPassword }} 
              run: flutter build appbundle --flavor YOUR_FLAVOR --obfuscate --split-debug-info=YOUR_PATH

            - name: Get release file aab path
              id: releaseAab
              run: echo "aabfile=$(find build/app/outputs/bundle -name '*.aab')" >> $GITHUB_OUTPUT

            - name: Get release file apk path
              id: releaseApk
              run: echo "apkfile=$(find build/app/outputs/apk -name '*.apk')" >> $GITHUB_OUTPUT

            - name: Upload Release Build to Artifacts
              uses: actions/upload-artifact@v3
              with:
                name: release-artifacts
                path: ${{ steps.releaseApk.outputs.apkfile }}

            - name: Upload AppBundle to Internal Testing
              uses: wzieba/step-google-play@v3
              with:
                serviceAccountJson: ${{ secrets.GOOGLE_PLAY_AUTH }}
                packageName: com.example.app
                source: build/app/outputs/bundle/release/app-release.aab
                track: internal

Modify the build.gradle sign section as folloging:

try {
                storeFile file("../keystore.jks")
                storePassword System.getenv("storePassword")
                keyAlias System.getenv("keyAlias")
                keyPassword System.getenv("keyPassword")
            } catch (Exception ignored) {
                storeFile keystoreProperties['storeFile'] ? file(keystoreProperties['storeFile']) : null
                storePassword keystoreProperties['storePassword']
                keyAlias keystoreProperties['keyAlias']
                keyPassword keystoreProperties['keyPassword']
            }