cleanup: Fixed the default case warning

Author: md-weber

lib/firebase_options_dev.dart

@@ -42,10 +42,12 @@ class DefaultFirebaseOptions {
           'DefaultFirebaseOptions have not been configured for linux - '
           'you can reconfigure this by running the FlutterFire CLI again.',
         );
-      default:
+      case TargetPlatform.fuchsia:
         throw UnsupportedError(
-          'DefaultFirebaseOptions are not supported for this platform.',
+          'DefaultFirebaseOptions have not been configured for fuchsia - '
+              'you can reconfigure this by running the FlutterFire CLI again.',
         );
+        break;
     }
   }