Don't override bounds when reparenting

Now that everything is in a hierarchy and inherit bounds,
reparenting shouldn't cause override bounds to be set.

This was causing bounds to be hard-coded incorrectly.

Bug: 156014697
Test: Launch into secondary repeatedly and observe no
      lasting blackness. Also can take a WM dump and
      verify that override-bounds are not unnecessarily
      set on tasks
Change-Id: I7b57a989869e52d9e665c9c86eda0c01ce30c997