Prevent reparenting to a fallback target while relaunching a pinned task

When relaunching a pinned task, excludes fallback launch target to
source task so the corresponding task organizer can handle the
relaunching properly.

Fix: 231976162
Test: atest TaskDisplayAreaTests
Test: repro steps in bug
Change-Id: I1ce7339f5f987ef79a6feb5847941951cd6dcb06
2 files changed