Changed parent assumption to current context user from USER_SYSTEM

After HSUM mode profile parent is not only limited to the SYSTEM user, changed the instances where it was using the SYSTEM to get the profile parent or to get the managed profile id to use the context user.

Also removed self user id check continue statement from getManagedProfileId() method to allow it to be getting queried by manged profile user itself in that case it will return it's own user id as the managed profile.

Test: manually verfied the flow in Settings app --> Password, passkeys and autofill --> Tap on Work profile.
Bug: 347693615
Flag: EXEMPT Minor bug fix
Change-Id: I54d52faed6c233afff8e9a6336d29afdff5c8268