Added Fdroid pre-release workflow

.github/workflows/pre_fdroid.yml

@@ -0,0 +1,65 @@
+on: workflow_dispatch
+name: Test, Build and Pre Release Fdroid apk
+env:
+  PROPERTIES_PATH: './android/key.properties'
+jobs:
+  build:
+    name: Build APK
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      # Setup Java environment in order to build the Android app.
+      - uses: actions/setup-java@v4
+        with:
+          distribution: 'zulu'
+          java-version: '17.x'
+
+      # Gradle cache for faster builds
+      - uses: actions/cache@v4
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*') }}
+          restore-keys: |
+            ${{ runner.os }}-gradle-
+
+      # Setup the flutter environment.
+      - run: |
+          pip install -U yq
+          echo "FLUTTER_VERSION=$(yq -r .environment.flutter pubspec.yaml | sed 's/\^//g')" >> $GITHUB_ENV
+      - uses: subosito/flutter-action@v2
+        with:
+          channel: 'stable'
+          flutter-version: "${{ env.FLUTTER_VERSION }}"
+
+      #
+      - run: |
+          echo keyPassword=\${{ secrets.KEY_STORE }} > ${{env.PROPERTIES_PATH}}
+          echo storePassword=\${{ secrets.KEY_PASSWORD }} >> ${{env.PROPERTIES_PATH}}
+          echo keyAlias=\${{ secrets.KEY_ALIAS }} >> ${{env.PROPERTIES_PATH}}
+      #
+      - run: echo "${{ secrets.KEYSTORE2 }}" | base64 --decode > android/app/key.jks
+
+      # Get flutter dependencies.
+      - run: flutter pub get
+      # Check for any formatting issues in the code.
+      - run: dart format --set-exit-if-changed .
+      # Statically analyze the Dart code for any errors.
+      - run: flutter analyze .
+      # Build universal apk.
+      - run: flutter build apk --release --flavor fdroid -t lib/main_fdroid.dart
+      # Release universal Fdroid pre-release apk.
+      - uses: svenstaro/upload-release-action@v2
+        with:
+          repo_name: gokadzev/Musify
+          repo_token: ${{ secrets.GITHUB_TOKEN }}
+          file: build/app/outputs/flutter-apk/app-fdroid-release.apk
+          asset_name: Musify_fdroid.apk
+          tag: ${{ github.ref }}
+          prerelease: true
+          overwrite: true
+          body: "**New Musify Fdroid Pre-Release!** \n
+          with pre-release / [BETA] builds you have access to the latest build of the app before it is released as stable-release version. Only use pre-release if you test the app, provide feedback, and help us improve its performance. Please note that pre-release versions of the app may be pretty unstable. You may experience crashes, bugs, or other issues while using the app. This is because pre-release version is still in development.
+          "