Themes: Allow theming navbar bg color

Change-Id: I256afc30fc018ea752769029c5246bc7310c23a6
Signed-off-by: Chet Kener <Cl3Kener@gmail.com>
SystemUI: Restore bounds when loading new gradient

This fixes an issue introduced with the reloading of the nav bar
transitions after a theme change in Change-Id: I256afc30fc018ea752769029c5246bc7310c23a6

Change-Id: I648039506b826583d554b2a0cf4f6ab9a9bb1de8
Signed-off-by: Chet Kener <Cl3Kener@gmail.com>
SystemUI: Separate system bar BGs for themes

This commit separates the navigation bar background colors from the
status bar background colors which allows more modular theme-ability.
Backwards compatibility for the old system bar values is still
preserved, but the new values are to be prioritized.

Thanks to Arz Bhatia for the suggestion.

Change-Id: Ibe579d16ea35ca5bdcfe9f98143c3f91cd24900f
Signed-off-by: Chet Kener <Cl3Kener@gmail.com>

Conflicts:
	packages/SystemUI/res/values/purity_colors.xml

Signed-off-by: Chet Kener <Cl3Kener@gmail.com>

Conflicts:
	core/res/res/drawable/scrubber_control_selector_holo_light.xml