title: Retrieve firebase data in the same order as its added
body: <p>How do I retrieve the firebase list in the same order as it is added.
  Looks like I’m getting them in a random order. I need to have them in order to draw my polyline in correct order.</p>
  
  <pre><code>List&lt;LatLng&gt; latLngList = new ArrayList&lt;&gt;();
  ref.addValueEventListener(new ValueEventListener() {
      @Override
      public void onDataChange(DataSnapshot snapshot) {
          for (DataSnapshot direction : snapshot.getChildren()) {
              if (direction.getKey().equals(firebaseKey)) {
                  MyLatLng wantedDirection = direction.getValue(MyLatLng.class);
                  for (Waypoints waypoint : wantedDirection.getWaypoints().values()) {
                      double lat = waypoint.getLatitude();
                      double lang = waypoint.getLongitude();
                      LatLng latLng = new LatLng(lat, lang);
                      latLngList.add(latLng);
               }
  </code></pre>
  
  <p>I want the JSON file to be in the same order as it the entries were added to the firebase list:</p>
  
  <pre><code>{
    "timeStamp" : "2016-05-03 23:06:05",
    "waypoints" : {
      "-KGsf4xB_rZbsAMW4I2D" : {
        "latitude" : 58.338713,
        "longitude" : 11.90885
      },
      "-KGsf5M9YtZn6Yq22Kts" : {
        "latitude" : 58.339218,
        "longitude" : 11.910351
      },
      "-KGsf5qSV3X7cAIBtANF" : {
        "latitude" : 58.340572,
        "longitude" : 11.915417
      },
      "-KGsf6oww79POAY_e7kf" : {
        "latitude" : 58.342271,
        "longitude" : 11.921562
      },
      "-KGsf7JBaac5o7VMEZMh" : {
        "latitude" : 58.344006,
        "longitude" : 11.926909
      },
      "-KGsf7nGpMEgPA0j1rRl" : {
        "latitude" : 58.345594,
        "longitude" : 11.929302
      },
      "-KGsf8HjFtn7Dxpx-DpO" : {
        "latitude" : 58.347846,
        "longitude" : 11.931577
      },
      "-KGsf8ltvEBeqXE_me8Z" : {
        "latitude" : 58.350397,
        "longitude" : 11.932334
      }
    }
  }
  </code></pre>