Ensure app can run reliably in background

[kalynstricklin]

• Foreground service exists, but we need to handle restart failure. SensorHubService.java The wakelocks are released. No proper error handling at all and fails silently.

  try {           
      sensorhub.start();
  } catch (SensorHubException e) {
      e.printStackTrace();   // ← user is not informed of whats happening. 
      releaseWakeLocks();    // ← locks released, but service keeps running                                                                  
  }