Fix pip expand issue if parent task under split root

If task have more than one activity and enter pip mode, WMS will
create new task for that activity and reparent it back when it
exit pip mode.

This cause some issues if the origin task under split root such
as UI abnormal or it cannot expand to fullscreen.(We expect it
expand to fullscreen always when click expand button on pip.)

Fix this by record the origin task id in taskInfo and use this
id to check exit split first or not if such task still under split
root when exit pip.

Fix: 264002510
Test: manual
Test: pass existing tests
Change-Id: I673f8c7a677f16897700d2be3853d4b4a36df7dd