Smartspace - Do not listen for user changes

The KeyguardClockSwitchController will already be recreated on a user
switch. This was adding a 2nd call, and then attempting reload
smartspace on a detached view.

Fixes: 187467770
Test: atest KeyguardClockSwitchControllerTest
Change-Id: I1f153c029481fe4915d42f7334cbb9534f89a42b