ThemeOverlayController: Ensure we always disable the neutral overlay

* Skipping neutral overlays is not enough. We need to explicitly disable neutral overlays
  and enable black theme.
* Code ref for getOverlayID: https://github.com/yaap/packages_apps_YASP/commit/fda23fa5e9ac4e44f9ac2786afbf531a307be4a3



Change-Id: Ie4310d65dadb71d7151b2e1a87eea92dec5f0d55
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>