Implement new bubble animation when collapsed

Bounce the bubble bar when a new bubble is received while the bubble
bar is collapsed.

Demo: http://recall/-/bJtug1HhvXkkeA4MQvIaiP/fn7NWNY3htuR6K3wxhfcK2

Flag: com.android.wm.shell.enable_bubble_bar
Bug: 280605790
Test: atest BubbleBarViewAnimatorTest
Change-Id: I4c622454fd99f6bb5a332b3fe4aa2764c8af93af