title: Appcelerator iOS Rich Push Notification not showing image when sent through FCM
body: <p>I am trying to send the rich notification in my iOS App. I am using the FCM to send the notification. Below is the payload as mentioned <a href="https://stackoverflow.com/a/42533430/7420795">here</a>. I am using FCM Module(<a href="https://github.com/hansemannn/titanium-firebase-cloud-messaging" rel="nofollow noreferrer">https://github.com/hansemannn/titanium-firebase-cloud-messaging</a>). I am referring <a href="https://github.com/appcelerator-developer-relations/appc-sample-ios-push-notifications" rel="nofollow noreferrer">this</a> sample project and successfully added <code>UNNotificationServiceExtension</code> in my Titanium project. 
  But the problem here is that, I am receiving normal Notification only, image is not visible in the notification panel.</p>
  
  <pre><code>{
      "to": "e4DgI95lsPA:APA91bHFX9MUmJ....",
      "content_available": true,
      "mutable_content": true,
      "click_action": "DOWNLOAD_CONTENT",
      "data": {
          "message": "Offer!",
          "attachment-url": "https://upload.wikimedia.org/wikipedia/commons/thumb/2/2a/FloorGoban.JPG/1024px-FloorGoban.JPG"
      },
      "notification": {
          "body": "Enter your message",
          "sound": "default"
      }
  }
  </code></pre>