build_universal_apk as job template

flutter/flutter-android.gitlab-ci.yml

@@ -39,7 +39,7 @@ android:
   after_script:
     - mv ${APP_DIRECTORY}/build/app/outputs/bundle/release/app-release.aab ./{APP_NAME}.aab
 
-apks:
+.build_universal_apk:
   stage: build
   image: 
     name: ${FLUTTER_ANDROID_IMAGE}