RelayBufferAnimate.java

latLngPublishRelay
  .buffer(2)
  .observeOn(AndroidSchedulers.mainThread())
  .subscribe(new Consumer<List<LatLng>>() {
     @Override
     public void accept(List<LatLng> latLngs) throws Exception {
       emission++;
       animateCarOnMap(latLngs);
     }
});