Merge "Only setup SecondaryDropTarget in onDragStart" into tm-dev am: a2ecf75082 am: 9899c3f028

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/18580266

Change-Id: Ib8da8d3fa08aad0335b9d5cfcf50e2a5c2f12dbd
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>