Clip BubbleBarExpandedView for IME

Respond to IME positioning changes and clip the BubbleBarExpandedView
to make sure there's no overlap with the IME.

Next I'll add logic to translate the expanded view if there's enough
space above it to reduce clipping.

Flag: com.android.wm.shell.enable_bubble_bar
Bug: 377329425
Test: atest BubbleBarExpandedViewTest
Change-Id: I5136b37f1d4e2eaab077fe29c57cbf96777c3d5a