Configure System theme [2/2]

Allow to force light or dark or use the wallpaper based
automatic selection

[Kshitij Gupta]

- Add a preference controller so as to adapt code for Display Settings
- Refactor some variables. We're theming System, not just SystemUI

Change-Id: Ia2361b9db7009e2a3806b65b22c7e0532e6ebeed
Signed-off-by: Josh Fox (XlxFoXxlX) <joshfox87@gmail.com>
4 files changed