title: Android Heads Up notification not showing up
body: <p>I am not able to find where i am getting wrong in building the Notification.</p>
  
  <p>I want the notification to show at top when phone is active and
  on lock screen when phone is in sleep.</p>
  
  <p>Here is the code that i have tried. But not able to achive the result.</p>
  
  <pre><code>PendingIntent pendingIntent = PendingIntent.getActivity(context,0, openIntent,PendingIntent.FLAG_UPDATE_CURRENT);
  
  NotificationCompat.Builder builder = new NotificationCompat.Builder(context, "Normal")
      .setSmallIcon(R.drawable.ic_folder)
      .setContentIntent(pendingIntent)
      .setPriority(NotificationCompat.PRIORITY_MAX)
      .setCategory(NotificationCompat.CATEGORY_MESSAGE)
      .setVibrate(new long[] {1000})
      .setContentTitle(mainListItem.getTitle())
      .setContentText(mainListItem.getDetail())
      .setSound(RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION))
      .setAutoCancel(true)
      .setVisibility(NotificationCompat.VISIBILITY_PUBLIC);
  
  
  NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
  
  notificationManager.notify(0,builder.build());
  </code></pre>