Allow non-leaf task to be moved to top

Non-leaf task was not able to moved to top because the task
was created from another user. Therefore, home task didn't
moved to top when entering split-screen on secondary user.

Check if the topmost task is current profile instead.

Bug: 154237928
Test: atest TaskStackTests
Change-Id: Iffa80d0bbadd3a54dcae3da6282aeafa094b0819