Bound drop target layout values to left and right. am: 3c0f4c15 am: 781c68b2 am: a8b8de1f

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



Change-Id: I2220ee2e7e82d24475d0f0bcd7e6f9c586b098a2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>