Update both width and height in BubbleBarView

We currently only update the width of the bubble bar but the
height is only updated when the icon size changes, so it's often
inaccurate. This affects screenshot testing where the bubble bar
isn't fully visible in the screenshot.

Flag: com.android.wm.shell.enable_bubble_bar
Bug: 355454021
Test: manual
       - used the bar normally to make sure it's not broken
Change-Id: If780308e10e7478a3651654e5fc2b3f9c4e36c14