Add back support for force resize developer option.

This functionality was lost when resizable was separated for PiP and
split screen. This changelist brings back this functionality by
taking the developer option flag into account when the TaskRecord
reports its support for split screen.

Fixes: 64010770
Test: turn on force resizable in developer settings, enter split
      screen with non-resizable task in the foreground.
Change-Id: I103943f0400389cac19f799b4e64e0607330f271