Avoid drawing live tile behind recents when launching on grid overview

Fix: 304911154
Flag: none
Test: Swipe up in tablet, scroll to side, launch focused task
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:1f5de2483bc9eb36128a7f700ca4539591afd186)
Merged-In: I91dd8b4088f02af9dc5e603853d8e26606acc38f
Change-Id: I91dd8b4088f02af9dc5e603853d8e26606acc38f