Update kernel to builds 9643945 am: 588989c020 am: 8bdffbaa68

Original change: https://android-review.googlesource.com/c/kernel/prebuilts/4.19/arm64/+/2455306

Change-Id: I46db8064b6898e38ff69ddc399de89b0880f7e1f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>