Merge "Completely remove pinned task when starting a new PiP" into tm-dev am:...

Merge "Completely remove pinned task when starting a new PiP" into tm-dev am: bfbf74ae am: a43d779a

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/18175783



Change-Id: I905ea3c2cd514bcf025181a096c6c9ad81b62ca5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>