Fix bubble bar arrow visibility during animation

Bubble bar pointer arrow was being drawn outside of BubbleBarView
bounds.
This caused issues when alpha was applied to the BubbleBarView. With
alpha, BubbleBarView draw was clipped to its bounds and arrow was no
longer visible. This led to the arrow flickering during move animations.
Move animation updates alpha.
Move the pointer arrow inside the bounds of the bar view. Update the bar
height to include the arrow.
Update callers who rely on bubble bar content height to take into
account extra height for the arrow.

Bug: 313661121
Flag: ACONFIG com.android.wm.shell.enable_bubble_bar DEVELOPMENT
Test: move bubble bar left and right, observe arrow is visible
Change-Id: I05866b5c944361b2f10437c3641527ed3c594047