title: No event listener removal for Firebase DatabaseReference?
body: <p>Hey do I need to remove this listener at some point, or does it get removed on its own? I have this called in a fragment within my activity, and users can go to another view without this one being destroyed. Therefore not sure if I am somehow suppose to remove this in an <code>onDestroy</code>, <code>onPause</code> call? I do not see a way to remove it since it is a <code>DatabaseReference</code> </p>
  
  <p>Here is the code:</p>
  
  <pre><code>private DatabaseReference mDatabase;
    mDatabase.child("projects").orderByChild("viewCount").limitToLast(15).addChildEventListener(new ChildEventListener() {
              @Override
              public void onChildAdded(DataSnapshot dataSnapshot, String s) {
  </code></pre>