Use additional scrim for lowLight ambientWallpaper

Fix doze scrim opacity logs (before the conversion to
log was always printing a scrim opacity of 0).

Test: atest DozeScreenBrightnessTest
Test: observe logs
Flag: EXEMPT bugfix
Bug: 419917011
Change-Id: Ia1e359f75be250321fa907f6a92d340313ec05a2