TIF: update condition in startUser

The current condition of `parentInfo.id == mCurrentUserId` should be
removed because this condition assumes that user can only switch to kid
user from main user. This condition leads to profile switching between
kid user 1 to kid user 2 to fail, leading to functional issues. As all
adult profiles all have user id of 0, there is no need to check the
value of profile's parent id either.

Bug: b/426052909
Test: verified by partner
Flag: EXEMPT bugfix only
Change-Id: I8d60c98735d250558fb0c6f4491ace9f0e90bb37