Reset HUN clipping after cancellation of disappearing animation

If the disappear animation of a notification is canceled before it
finishes, the clipping of the notification may remain in an
inconsistent state. This would leave the notification clipped until it
starts another HUN appear/disappear animation.

Test: atest ExpandableNotificationRowTest
Bug: 356958336
Flag: EXEMPT trivial bugfix
Change-Id: I1a35f0e34d24c6f7889d26a3ff0a8edca286b253