[LowLightBoost] Reduce night mode threshold

- reducing from 100 to 90 for avg scene luma pass / fail threshold

Bug: 347150790
Test: n/a
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:7ead431cab4a0c82dbeee010cf8c7a8eb078b100)
Merged-In: I465e366af8d8e5ceef8a1855894d91a18e783d0b
Change-Id: I465e366af8d8e5ceef8a1855894d91a18e783d0b