Avoid clipping when a notification is translating.

Clipping may occur if a notification is being translated quickly by a
gesture or by a magnetic animation when the notification is inside a
notification group. In this change, the proposal is to invalidate the
NotificationChildrenContainer when translating an
ExpandableNotificationRow to make sure that the latest translations are
considered in the clipping path.

Test: manual. Verified clipping does not happen when swiping a
  magnetic notification and when re-attaching a notification.
Flag: com.android.systemui.magnetic_notification_swipes
Bug: 408059305

Change-Id: I58e7c2b17d814721918260667a7ddf0318721cde