Scroll wallet and controls under power menu.

Bug: 150694556

Test: Manual -- wallet and controls scroll beneath power menu, and clicking/swiping them works as expected. User can still dismiss the menu by tapping on any empty space and power menu controls are still functional in all three current layouts (column, grid, grid_v2) in portrait/landscape/seascape.

Change-Id: I31de9661fdcd794c845c5e0040c490bf1520cb65