Controls UI - Fix dropdown layer list

Remove bottom layer, not needed in this case. This will prevent the
icon from hovering over the window and not obeying animations.

Fixes: 156662716
Fixes: 156924481
Test: manual. show/hide power menu, and scroll it up
Change-Id: If7c66e68ad582143d2ecd29e0c5938070996a9f9
2 files changed