MapsActivity.java

 @Override
    public void onMapReady(GoogleMap googleMap) {
        mGoogleMap = googleMap;

        mLocationRequest = new LocationRequest();
        mLocationRequest.setInterval(120000); // two minute interval
        mLocationRequest.setFastestInterval(120000);
        mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);

        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (ContextCompat.checkSelfPermission(this,
                    Manifest.permission.ACCESS_FINE_LOCATION)
                    == PackageManager.PERMISSION_GRANTED) {
                //Location Permission already granted
                mFusedLocationClient.requestLocationUpdates(mLocationRequest, mLocationCallback,
                        Looper.myLooper());
                mGoogleMap.setMyLocationEnabled(true);
            } else {
                //Request Location Permission
                checkLocationPermission();
            }
        } else {
            mFusedLocationClient.requestLocationUpdates(mLocationRequest, mLocationCallback,
                    Looper.myLooper());
            mGoogleMap.setMyLocationEnabled(true);
        }
    }