PIP should only move along long edges when on phone

Phone portrait: restrict movement to left / right edges
Phone landscape: restrict movement to top / bottom edges

Tablet: allow PIP on all edges regardless of orientation

Test: manual - have PIP try to move along top / bottom edge
in phone portrait, and left / right edge in phone landscape
Fixes: 35358644
Change-Id: Ie50ae220782936942d1bcd8d9251d7275832a47f