java.lang.IllegalStateException: Not on the main thread Google Maps

you must run this code in the UIThread:

activity.runOnUIThread(new Runnable(){
    public void run(){
        mGoogleMap.addPolyline(new PolylineOptions().add(latLng));
        mGoogleMap.animateCamera(CameraUpdateFactory.newCameraPosition(new CameraPosition.Builder().target(latLng)
        .zoom(13).build()));
    }
});