Fix the missing HUN removal animation for delayed group notification

Fix the missing HUN removal animation for delayed group notification.
The child notifs are not promoted in the pipeline during HUN removal
animation, because BaseHeadsUpManager.isHeadsUpEntry returned false.
This change added a status check to make sure they are correctly
promoted and not being grouped in the pipeline during the HUN
removal animation.

Fix: 343475993
Test: HeadsUpCoordinatorTest
Flag: com.android.systemui.notification_group_hun_removal_animation_fix
Change-Id: I5346d01114054a52f24bb3de2b90c9bab37b7bbc