Fix VirtualDeviceManagerService startUser crash

Service crashed on certain secondary user startups because the system
server was being denied permission within the system server.

Test: on headless user 0 mode device, start a secondary user and ensure
that the service doesn't crash on startup
Test: atest CreateUsersNoAppCrashesTest (with ag/16771988)
Bug: 217246676

Change-Id: I98ba584553ca0cc0b03fc9196c841645faca1ddc