Animate the bubble bar to show new bubble

This change updates that animation that plays when a new bubble notification is received. We now animate the entire bubble bar rather than the individual bubble.

Demo: http://recall/-/bJtug1HhvXkkeA4MQvIaiP/dwbsZJZlqLwJ2IG7RfJZ7c

Flag: ACONFIG com.android.wm.shell.enable_bubble_bar DEVELOPMENT
Bug: 280605846
Test: atest BubbleBarViewAnimatorTest
Change-Id: I2dc58ad61b880d76c9eefa462c3aee4e8bbb3584