1. Define default Themes for autofill window and save dialog.
(http://go/theme_autofill). Phone uses light themes, TV uses
dark themes.
2. Apply autofill theme to RemoteViews passed from autofill service.
So this can make sure the textColor of RemoteViews matches
the background of autofill theme uses.
Updated public javadoc that autofill service should not
hardcode color values.
3. A new TV ux that occupies half screen height (go/autofill-for-tv).
TV autofill now passes unhandled physical keyevent to app window
in the same way phone/tablet does.
4. Fixed ATV autofill window to be SYSTEM_DIALOG, so it wont be
clipped by app activity window (DialogLauncherActivityTest).
Bug: 71720680
Bug: 74072921
Test: CtsAutofillTest
Change-Id: Ib570227b0958b1800e8f0600b8aec36478568d74
36b86c28f8