Add TaskFragmentOrganizer#applyTransaction with request transition

Instead of having WM Core to "guess" when to request transtiion, let the
organizer to tell whether or not it needs to be applied immediately.

With the shouldApplyIndependently parameter, we can make sure the future
runtime API to change split layout won't affect other ongoing
transition.

Bug: 207070762
Test: atest WmTests:TaskFragmentOrganizerControllerTest
Change-Id: I658b0ba1ae9decc741f09cb53bfff2c45ea076a0