Add navbar background preview to ThemesContract

Change-Id: Id3ed43c86649b1757fec7f3fc7dee2d2730258e2
Add column for tracking when a theme was installed

Change-Id: Ie8d13aaaf968c21d765062ae598fdac62caa7b2d
HOVER: A few improvements

- Better touch outside touch input handling
- On touch outside hide both case (expanded and non) in 1.25 secs
- Tweak clear foreground notification when we are on the same app
- Code style
- Tiny cleanup

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
Change-Id: Ibb0c7c09ae3256bbf744f359cca651c8cb8112d9