Use binned brightness sensor instead of prox

Prox can be noisy and should only be used as a fallback when a more
robust sensor implementation is not available.

Test: manually cover prox sensor
Test: breakpoint
Test: dumpsys
Fixes: 137451005
Change-Id: If0fca42aca36546942930ce76be1353129fc91fc
(cherry picked from commit f61c1044)