Execute WCT when showDesktopApps is called

When shell transitions were enabled, we were not exeucting the WCT that
brings desktop apps to front.
Ensure that this is called when shell transitions are enabled.

Bug: 254738174
Test: atest DesktopModeControllerTest
Change-Id: Ie8391867a1d89ecdab7cbd5afd8cd80ecdc5b78c
1 file changed