Limit freeform to front for freeform task launches

When freeform tasks are visible and user attempts to go home, it
triggers a TRANSIT_OPEN transition with target as home screen.
Our current logic checks for TRANSIT_OPEN and brings all freeform apps
to front when this is detected.
Limit bringing freeform apps to front only if a freeform task launches.
Otherwise skip.

Bug: 254736507
Test: atest DesktopModeControllerTest
Change-Id: Ib1ec6449e5236d6e34efdad277fb35bfda7bd068