Changed CarServiceHelperService so it pre-creates users after every boot

Bug: 111451156
Bug: 132111956
Bug: 140750212

Test: manual verification on automotive running:

   adb reboot-bootloader && fastboot -w && fastboot reboot

 then waiting and running:

   adb shell cmd user list --all -v

Merged-In: Ibaeae52723bcd6d04c41ff0c5dda3849a262f99a
Change-Id: Ibaeae52723bcd6d04c41ff0c5dda3849a262f99a
(cherry picked from commit 2d08c7a1812952b2db1099a2847d8d6890744430)