Fix race condition wen setting boot color sysprops (round 2)

Bug: 197690550
Test: ThemeOverlayApplierTest, ThemeOverlayControllerTest. Set wallpaper
and reboot.

Change-Id: I7d304d442e3f6839ad047944cae21dc07d7c3dea
Merged-In: I7d304d442e3f6839ad047944cae21dc07d7c3dea
4 files changed