Merge "When KEYCODE_BACK is received, hide keyboard" into sc-dev am: 24c8ebd88d am: 5d52dc0201 am: cbab278489

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

Change-Id: I2ee370af0dcb2b43a35695d126598a534276ee0d