Merge "When KEYCODE_BACK is received, hide keyboard" into sc-dev am: 24c8ebd88d am: 5d52dc0201

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

Change-Id: I220fbd2740df73b15805300767b0c1a7bf3617d8