Merge "Use feature flag in Settings." into master

Merge commit 'd76261e04cce4245a3ea3f7b0e6d903d39631c49' into faster_emergency_feature_flag

Manually merge this commit from pi-dev-plus-aosp to goog/master to
resolve a merge conflict.

Bug: None
Test: I solemnly swear I tested this conflict resolution.
Change-Id: I9b226742c5eaf8b933e273688bf4e22c650dec46