Respect the orientation of a home activity in the process of launching when split-screen enabled.

The home activity in the process of launching isn't considered visible
(isVisible() returns false) since an app transition prevents the value
from being committed. This ensures that the orientation value returned
for TaskDisplayArea#getOrientation() also takes into account home
activities currently in the process of launching when split-screen is
enabled.

Fixes: 159473343

Test: Install non-resizable 3P home. Enter split screen primary with
recents on secondary, rotate device, navigate back.
Test: TaskDisplayAreaTests#testGetOrientation_nonResizableHomeStackWithHomeActivityPendingVisibilityChange

Change-Id: I0b14bbe222a13ecdfc3245af2ae7db75eb374e7a