settings: Auto-brightness levels shouldn't fill the screen

On tall displays this ends up with a lot of useless padding
in the list.

Change-Id: I998b86ec12d531cf1db08db7d9c23d12d8641730
settings: Unbreak wifi display on tablets

In change 46af8086db0db5b41f20c9f05a5f42c182262576 the option
to enable/disable the wireless display was moved to an action
bar which ends up entirely removing the ability to enable it
for devices using Settings in tablet (multi-pane) mode.

Follow the pattern of dreamcast which correctly displays
and removes the action bar.

Change-Id: Ie82b04b5e96a59ec093323601f8e79d23a6e69de