Restriction setters were not getting called since we changed the boot
sequence for multi-user model.

Introduces a Setting to check whether restrictions for Guest and System
user have already been set, and if not, sets them.

Each restriction setter writes to disk, so we only want to do it once.

Change-Id: I0e2e997324c41b70688204719d699bd34394352f
Fixes: 115415416
Fixes: 112798377
Test: atest CarUserServiceTest
3 files changed