Hide multi user switcher on keyguard screen when disabled

The visibility of multi user switcher on keyguard will be the same as
quicksettings multiuser switcher with this change. Added corresponding
test as well.

Bug: 227232316
Test: Manually Test, multiuser switcher does not show when device is
managed by finance DO;
Test: atest NotificationPanelViewControllerTest

Change-Id: I97baa995a422c071c925848b2c3f397851d3cea9