[AA+] Add LAUNCHER_ALLAPPS_KEYBOARD_CLOSED event. am: aafa8a44a3

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/13486540

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I653a985980cb85bf81ec83244e35b932697ad437