Update flutter-android.yml

.github/workflows/flutter-android.yml

@@ -28,9 +28,13 @@ jobs:
     - name: Install dependencies
       run: flutter pub get
 
-    - name: Write google-services.json
+    - name: Decode and write google-services.json
       run: |
-        echo "${{ secrets.GOOGLE_SERVICES_JSON }}" | sed 's/\\n/\n/g' | tr -d '\r' > android/app/google-services.json
+        echo "${{ secrets.GOOGLE_SERVICES_JSON }}" | base64 --decode > android/app/google-services.json
+
+    - name: Validate google-services.json
+      run: |
+        cat android/app/google-services.json | jq empty
 
     - name: Decode and add the signing key
       run: |