Revert "Cache the UserInfo for the system user on UserManagerService."

This reverts commit ae7902fcefeb0489b6b7360322594ab7bee634df.

Reason for revert: Bisection indicates this has broken work profile unfortunately: http://b/165780705

Change-Id: I0de7abdf907b1a52896171ab10d91fac2bb744ca
1 file changed