Add onKeyEvent, to support KEYCODE_HOME

- Also added displayId to onBackEvent

Bug: 381339822
Flag: com.android.launcher3.home_button_uses_keycode_home
Test: Manual, OverviewCommandHelperTest
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:622a882e1f17d108a336ecfd3e4eb7aa9707f1e6)
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:0f46d701bb4d6d81106e9a5a0a13e7237d311efa
Merged-In: I55e2ee7adfa40c9d8f289a2b4c76aa12f80e78c3
Change-Id: I55e2ee7adfa40c9d8f289a2b4c76aa12f80e78c3