title: Android: Grouped notifications and summary still shown separately on 4.4 and below
body: <p>I want to implement <a href="https://developer.android.com/training/wearables/notifications/stacks.html">stacked notifications on Android Wear</a> To do that I create 1 summary notification and N individual notifications for each "item". I want only the summary to be shown on the phone. Here's my code:</p>
  
  <pre><code>private void showNotifications() {
      NotificationManager notificationManager = (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
      showNotification1(notificationManager);
      showNotification2(notificationManager);
      showGroupSummaryNotification(notificationManager);
  }
  
  private void showNotification1(NotificationManager notificationManager) {
      showSingleNotification(notificationManager, "title 1", "message 1", 1);
  }
  
  private void showNotification2(NotificationManager notificationManager) {
      showSingleNotification(notificationManager, "title 2", "message 2", 2);
  }
  
  protected void showSingleNotification(NotificationManager notificationManager,
                                        String title,
                                        String message,
                                        int notificationId) {
      NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
      builder.setContentTitle(title)
              .setContentText(message)
              .setSmallIcon(R.mipmap.ic_launcher)
              .setGroupSummary(false)
              .setGroup("group");
      Notification notification = builder.build();
      notificationManager.notify(notificationId, notification);
  }
  
  private void showGroupSummaryNotification(NotificationManager notificationManager) {
      NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
      builder.setContentTitle("Dummy content title")
              .setContentText("Dummy content text")
              .setStyle(new NotificationCompat.InboxStyle()
                      .addLine("Line 1")
                      .addLine("Line 2")
                      .setSummaryText("Inbox summary text")
                      .setBigContentTitle("Big content title"))
              .setNumber(2)
              .setSmallIcon(R.mipmap.ic_launcher)
              .setCategory(Notification.CATEGORY_EVENT)
              .setGroupSummary(true)
              .setGroup("group");
      Notification notification = builder.build();
      notificationManager.notify(123456, notification);
  }
  </code></pre>
  
  <p>This works just fine on Android 5.1, only the summary is shown in the phone's notification bar:</p>
  
  <p><img src="https://i.stack.imgur.com/I8JVx.png" alt="enter image description here"></p>
  
  <p>But on Android 4.4 it also shows individual notifications 1 and 2:</p>
  
  <p><img src="https://i.stack.imgur.com/sSQsE.png" alt="enter image description here"></p>
  
  <p>In both cases notifications on Android Wear are shown in a stack, as desired. How do I make Android 4.4 only show the summary notification in the notification bar?</p>