title: Android - open or restart app after clicking push notification using flag activities
body: <p>I am using push notifications in Android. When I receive a push notification, I want to open the application if it is still running, else it should open a new instance of it.</p>
  
  <p>I am using</p>
  
  <pre><code>PendingIntent contentIntent = PendingIntent.getActivity(this, 0, notificationIntent, 
      Intent.FLAG_ACTIVITY_CLEAR_TOP | 
      Intent.FLAG_ACTIVITY_SINGLE_TOP | 
      Intent.FLAG_ACTIVITY_NEW_TASK);
  </code></pre>
  
  <p>But when I receive a push notification now and I click on it, nothing happens.</p>
  
  <p>How can I still achieve this by using flagIntents?</p>