Исключение во время выполнения приложения (ошибка не генерируется)

Question

Я изучаю отслеживание активов отсюда Приложение успешно скомпилировано без ошибок (режим энергосбережения выключен). Но приложение в моем телефоне внезапно останавливается, показывая уведомление об исключительной ситуации во время выполнения. Вот мой код:

TransportActivity.java

public class TrackerActivity extends Activity {

  private static final int PERMISSIONS_REQUEST = 1;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_tracker);
  // Check GPS is enabled
  LocationManager lm = (LocationManager) getSystemService(LOCATION_SERVICE);
  if (!lm.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
  Toast.makeText(this, "Please enable location services", Toast.LENGTH_SHORT).show();
  finish();
  }

  // Check location permission is granted - if it is, start
  // the service, otherwise request the permission
  int permission1 = ActivityCompat.checkSelfPermission(this,
  Manifest.permission.ACCESS_FINE_LOCATION);
  int permission2 = ActivityCompat.checkSelfPermission(this,
  Manifest.permission.FOREGROUND_SERVICE);
  if (permission1 == PackageManager.PERMISSION_GRANTED && permission2 == PackageManager.PERMISSION_GRANTED) {
  startTrackerService();
  } else {
  ActivityCompat.requestPermissions(this,
  new String[]{Manifest.permission.ACCESS_FINE_LOCATION,Manifest.permission.FOREGROUND_SERVICE},
  PERMISSIONS_REQUEST);
  }
  }

  private void startTrackerService() {
  startService(new Intent(this, TrackerService.class));
  finish();
  }

  @Override
  public void onRequestPermissionsResult(int requestCode, String[] permissions, int[]
  grantResults) {
  if (requestCode == PERMISSIONS_REQUEST && grantResults.length == 1
  && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
  // Start the service when the permission is granted
  startTrackerService();
  } else {
  finish();
  }
  }
}

TransportService.java

public class TrackerService extends Service {

  private static final String TAG = TrackerService.class.getSimpleName();

  @Override
  public IBinder onBind(Intent intent) {return null;}

  @Override
  public void onCreate() {
  super.onCreate();
  buildNotification();
  loginToFirebase();
  }

  protected BroadcastReceiver stopReceiver = new BroadcastReceiver() {
  @Override
  public void onReceive(Context context, Intent intent) {
  Log.d(TAG, "received stop broadcast");
  // Stop the service when the notification is tapped
  unregisterReceiver(stopReceiver);
  stopSelf();
  }
  };

  private void buildNotification() {
  String stop = "stop";
  String channelId="my_channel_id";
  registerReceiver(stopReceiver, new IntentFilter(stop));
  PendingIntent broadcastIntent = PendingIntent.getBroadcast(
  this, 0, new Intent(stop), PendingIntent.FLAG_UPDATE_CURRENT);
  // Create the persistent notification
  NotificationCompat.Builder builder = new NotificationCompat.Builder(this, channelId)
  .setContentTitle(getString(R.string.app_name))
  .setContentText(getString(R.string.notification_text))
  .setOngoing(true)
  .setContentIntent(broadcastIntent)
  .setSmallIcon(R.drawable.ic_tracker);
  startForeground(1, builder.build());
  }

  private void loginToFirebase() {
  // Authenticate with Firebase, and request location updates
  String email = getString(R.string.firebase_email);
  String password = getString(R.string.firebase_password);
  FirebaseAuth.getInstance().signInWithEmailAndPassword(
  email, password).addOnCompleteListener(new OnCompleteListener<AuthResult>(){
  @Override
  public void onComplete(Task<AuthResult> task) {
  if (task.isSuccessful()) {
  Log.d(TAG, "firebase auth success");
  requestLocationUpdates();
  } else {
  Log.d(TAG, "firebase auth failed");
  }
  }
  });
  }

  private void requestLocationUpdates() {
  LocationRequest request = new LocationRequest();
  request.setInterval(10000);
  request.setFastestInterval(5000);
  request.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
  FusedLocationProviderClient client = LocationServices.getFusedLocationProviderClient(this);
  final String path = getString(R.string.firebase_path) + "/" + getString(R.string.transport_id);
  int permission = ActivityCompat.checkSelfPermission(this,
  Manifest.permission.ACCESS_FINE_LOCATION);
  if (permission == PackageManager.PERMISSION_GRANTED) {
  // Request location updates and when an update is
  // received, store the location in Firebase
  client.requestLocationUpdates(request, new LocationCallback() {
  @Override
  public void onLocationResult(LocationResult locationResult) {
  DatabaseReference ref = FirebaseDatabase.getInstance().getReference(path);
  Location location = locationResult.getLastLocation();
  if (location != null) {
  Log.d(TAG, "location update " + location);
  ref.setValue(location);
  }
  }
  }, null);
  }
  }
  @Override
  public void onDestroy() {

  try{
  if(stopReceiver!=null)
  unregisterReceiver(stopReceiver);
  }catch(Exception e){}
  super.onDestroy();
  }
}

onDestroy() методв TrackerService.java - реализация, которую я сделал со своей стороны, потому что без этого приходила ошибка «Вы пропускаете unregisterReceiver() вызов» . Кроме того, база данных не создается в firebase.

И есть ли лучший источник для отслеживания местоположения в реальном времени? Поскольку я новичок, это было бы очень полезно для меня.