Bound drop target layout values to left and right. am: 3c0f4c15

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/18491881



Change-Id: I6b598501d70c663ba37928e9cdd9a5bb26085a51
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>