Settings: sync qs invert color with color inversion in Settings

Color inversion in settings is not consistent with the quick
settings tiles for the inverted color.
This patch registers the invert color settings variable to
content resolver to apply any change to it from either
qs tiles or settings menu.

Change-Id: Ib1433238d4985e930f3a1c650198dbeb05ccba52
Issue-id: FEIJ-164
(cherry picked from commit f252c251)