On some devices, we want the screen off transition to complete before
we start dozing. Added a new config.xml attribute config_dozeAfterScreenOff
to configure this behavior.
Defer starting dreams until the display is ready.
Fixed some minor issues in the system UI doze service when setting the
display state.
Bug: 16187655
Change-Id: Ib1bc60de5457166f4b4880732db5df989dda67a4