Allow extra pixel for app bounds containment PiP

Allow an extra one pixel delta on each side of the
app bounds for source-rect-hint containment checks
when swiping to enter PiP.

Bug: 349821386
Flag: EXEMPT bugfix
Test: swipe PiP to home with 21:9 video from landscape to portrait
Change-Id: Ibc53e426b49cfcd58e977433358b9980732ac289