Merge "When KEYCODE_BACK is received, hide keyboard" into sc-dev am: 24c8ebd88d am: efa47a13f4

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/15107283

Change-Id: I702e93ad4963a171b8dd7f5dc906205e8007b2dc