title: Push not received when app is killed
body: <p>I am using the new FCM to push message from my server to my android app.</p>
  
  <pre>
  {
      "to" : "APA91bHun4MxP5egoKMwt2KZFBaFUH-1RYqx...",
      "data" : {
        "Nick" : "Mario",
        "Room" : "PortugalVSDenmark"
      }
  }
  </pre>
  
  <p>I am able to push messages to my app using the new FCM however, when I kill the app (long press on home button then slide the app to the left), push messages are not delivered any more.</p>
  
  <p>Why? </p>