Update the current user again after registering UserChangeListener

Active user change event may not be caught by DesktopTasksController if
it happens between init and onInit() call.

Bug: 391666399
Test: manual - the correct Home activity is launched after minimizing
      the last task
Flag: EXEMPT - bug fix
Change-Id: I142ae3fc41dcb2021108748cc650a2016be510cb