title: Unable to use urban airship and Facebook cloud messaging together in iOS
body: <p>I have been using urban airship in my iOS app and my backend for push notifications. Recently, I had to migrate my phone number authentication from digits to firebase which involved using Firebase Cloud messaging. Firebase Cloud messaging does not work until I comment out the setup of urban airship. Is there a way to use both? What might be causing the problem? I don't want to change my current push notification setup for this migration.</p>
  
  <p>My AppDelegate currently looks like this:</p>
  
  <pre><code>func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -&gt; Bool {
      UIBarButtonItem.appearance()
          .setTitleTextAttributes([NSFontAttributeName : UIUtils.getFont(14)],
                                  for: UIControlState())
      FirebaseApp.configure()
  //        setupUrbanAirship()
      return true
  }
  func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
      // Pass device token to auth
      Auth.auth().setAPNSToken(deviceToken, type: AuthAPNSTokenType.sandbox)
  }
  
  func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable : Any]) {
      Auth.auth().canHandleNotification(userInfo)
  }
  
  func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable : Any],
                   fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -&gt; Void) {
      if Auth.auth().canHandleNotification(userInfo) {
          completionHandler(.noData)
          return
      }
  }
  fileprivate func setupUrbanAirship() {
      let filename = PropertyUtils.getUAPropertyFileName()
      let path = Bundle.main.path(forResource: filename, ofType: "plist")
      let config = UAConfig(contentsOfFile: path!)
  
      //config.automaticSetupEnabled = false
      UAirship.takeOff(config)
      let channelID = UAirship.push().channelID
      print("My Application Channel ID: \(channelID)")
      UAirship.push().userPushNotificationsEnabled = true
  }
  </code></pre>