Fixes opening task from Recents can be hidden.

The opening task from Recents can be invisible because there would hide
the created leash, which should be unnecessary since the recents window
animator would handle the cross fade animation.

Test: Enable shell transition, enter recents, swipe to right-most page(
the page shows "Clear all"), then click the task and verify the task
won't become invisible during animation. Test on both NexusLauncher and
3rd-party Launcher.
Test: atest FlickerTests:OpenAppFromOverviewTest
Test: atest TaplTestsQuickstep

Change-Id: I0f7b7855de944c744190f6599ed48490f6e0d9f0