Fix missing background where multiple KeyButtonViews are rendered in the

same window

getLeft(), getRight(), getTop(), getBottom() return coords in the entire
window, while drawOval asks for coords in the current view. This is not
an issue where only one KeyButtonView is in the layout, but it is when
there are more than one.

Fixes: 177153730
Test: Manual test with ag/q/topic:"game-dashboard-entry-point"

Change-Id: If781eb3cb98a3dfb6e51c431fec7f6ae909ef3a3