title: (Android + Firebase) Automatically sending push notifications on child added
body: <p>So I'm trying to make a group chat for an Android app using Firebase. What I want to do is send automatic notifications to users whenever a child is added to the realtime database (i.e when someone else sends a message to the group chat I want the other users to get a notification, regardless of if the app is in the forground or not).</p>
  
  <p>Does anyone have any experience doing this? I have been looking around and I haven't found any good answers. Not even sure it can be done using firebase.</p>