ci: run gradle build tests

.github/workflows/android.yml

@@ -2,6 +2,7 @@ name: Android CI
 
 on:
   push:
+    branches: [ master ]
   pull_request:
     branches: [ master ]
 
@@ -22,6 +23,8 @@ jobs:
         cp ./app/google-services-example.json ./app/google-services.json
         rm ./app/src/main/res/values/curfirmwareversion.xml
         cp ./app/special/curfirmwareversion.xml ./app/src/main/res/values/
+        rm -rf ./app/src/main/assets/firmware
+        mkdir -p ./app/src/main/assets/firmware
 
     - name: Set up JDK 11
       uses: actions/setup-java@v3
@@ -33,8 +36,8 @@ jobs:
     - name: Validate Gradle wrapper
       uses: gradle/wrapper-validation-action@v1
 
-    - name: Build debug APK
-      run: ./gradlew assembleFdroidDebug
+    - name: Gradle build
+      run: ./gradlew build
 
     - name: Upload debug APK
       uses: actions/upload-artifact@v3