anzu: Remove obsolete ALS configuration

Also set button_backlight current on pre_hw_config.sh to avoid too bright recovery indication.

Signed-off-by: Michael Bestas <mikeioannina@gmail.com>

Change-Id: I2a92ac59b573a6f48e52425d196702fb78cdb7c1
Merge "anzu: Remove obsolete ALS configuration" into jellybean