[Bubbles] Fix bubble disappear issue when quickly switching

When quickly switching back-and-forth between bubbles, there
is a chance that the animations will run out-of-order because
they wait for TaskView visibility. This change cancels the
out-of-date animation to prevent such issues.

Bug: 403612574
Test: Manual; atest BubbleBarAnimationHelperTest BubbleBarExpandedViewTest
Flag: EXEMPT bugfix
Change-Id: Ia9ba413bf5475d881bbed4d945ddad437b46b869