Revert "Multiuser: Check if valid user before starting service"

This reverts commit cd271a3a
which were preventing services from gettign started. Checks
are not required now as handling for socket listening is now
added in AdapterService code.

Change-Id: I3b819b3fe665951c3d7e0bca13a4da6287c8890e
CRs-Fixed: 992642