Check if notification group child is bundled and regroup when posted

 Check if summary & child notifications are not part of the same bundle after posting.
 The check is needed because if the notification was bundled while enqueued,
  NotificationAdjustmentExtractor is bypassed and regrouping is not triggered by GroupHelper#onChannelUpdate.

Flag: android.service.notification.notification_regroup_on_classification
Test: atest GroupHelperTest
Bug: 377382403
Change-Id: Ibcc21289bf64854a83422aff0d489dc1f9fe3453