Fix race in notifying user unlock to car service

- Sending notification after AM.unlockUser unlocks user but UserManager is
  returning false for isUserUnlockingOrUnlocked, and become problematic
  for additional checks inside car service.
- Remove that part as onUnlockUser is called anyway with right state.

Bug: 147788854
Test: reboot and check VendorServiceController to launch services
Change-Id: Icf4e157dd3a2bd08ef62bc044d069bffdb2cf454