add unsigned debug to github actions

.github/workflows/build-unsigned-debug.yml

@@ -0,0 +1,41 @@
+name: Flutter Build Unsigned Debug
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  build-app:
+    name: Build Unsigned APK
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        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:
+          channel: stable
+
+      - name: Cache pub dependencies
+        uses: actions/cache@v2
+        with:
+          path: ${{ env.FLUTTER_HOME }}/.pub-cache
+          key: ${{ runner.os }}-pub-${{ hashFiles('**/pubspec.lock') }}
+          restore-keys: ${{ runner.os }}-pub-
+
+      - name: Download pub dependencies
+        run: flutter pub get
+
+      - name: Build Debug Build
+        run: flutter build apk --debug --flavor main
+