Fix 5579440: Add transport control view to tablet unlock screens

This updated tablet layouts to support showing album art and transport
control views in PIN, pattern and password screens of lock screen.

It also allows the addition of a background protect asset and
the ability to show the system wallpaper on layouts that define a
transport_bg_protect view.

Also updated layout to use new ICS-style buttons on lock screen and
fixed bug with "forgot pattern" button where we were showing the
emergency call icon.

To avoid problems with leading ones in the mono-space clock font,
we now right-justify status text on tablet and remove the AM/PM
indicator.

Status font size adjusted by UX.

Added background protection drop shadow to transport control.

Fixed portrait mode to be right-justified when transport is showing.

Change-Id: I790292fc39f4588f87adc9d9241706817ae6baab