Fix bubbles animation when the new bubble added and old bubble removed.

The AddingAndRemoving animation now uses a newly selected bubble index
and added bubble index arguments.

Test: BubbleAnimatorTest
Test: Manual. Enable optional overflow bubble.
Create a bubble bar with overflow containing a single
bubble. Open the overflow menu and click an overflow bubble icon.
Observe that a new bubble is added and immediately expands while the
overflow bubble is collapsing. Observe that bubbles animation.
Test: Manual. Have few bubbles in the bubble bar. Collapse any bubble.
Observe bubbles are animated correctly.
Video: (slowed down 10 times)
http://recall/-/gx8ASgewUeUS3QYohfrd1J/emOREYETIeV5ktcNZLETYa

Flag: com.android.wm.shell.enable_bubble_bar
Fixes: 359952121
Change-Id: If2366ec12cb196757ba6439c5c9306959d4191a9