Fix flicker when entering PiP from split-screen / overview

This is a follow-up of ag/16418447 where we hide the Tasks in
split-screen mode on swipe-home-to-pip and here we use the same
mechanism when we are entering PiP from the overview and the pip-able
task is in split-screen mode.

Video: http://recall/-/aaaaaabFQoRHlzixHdtY/bNtg3ZOhuTBKm9nU9CPeNQ
Bug: 228289777
Test: follow the reproduce steps in bug, see video
Change-Id: Icab11d52cedaf94af0ee72023cebca8ec51d8851