Apply user-switch restoration logic in WMS#setCurrentUser

Otherwise it may be applied after the transition request is sent to
shell overwriting any of its custom restoration logic.

Flag: com.android.window.flags.apply_desk_activation_on_user_switch
Bug: 430988310
Test: switch users while desktops are active for both, check tasks are
restored correctly

Change-Id: Ib42d707d0f5c279042080c004044667a11c74f0c