Fix crash/flicker with taskbar when canceling drag and drop am: 729eb845

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/17776925



Change-Id: Ie965f2429a0b484e98dfed17d6bf702c11539c8f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>