getUserLogoutability() to have user id as argument

This hidden API is expected to be called by systemui, which is run by user 0. Thus mUserId is always 0 in systemui, so the return value would always be LOGOUTABILITY_STATUS_CANNOT_LOGOUT_SYSTEM_USER.

Instead, we should user's id as argument. The caller would pass the current user's id.

Bug: 380122753
Flag: EXEMPT bugfix
Test: m
Change-Id: I3a1492c3fec5c410e7c49603837d1cfddfeaf7f7