Update kernel to builds 8640382 am: 8f3e439221 am: 733093fe8f

Original change: https://android-review.googlesource.com/c/kernel/prebuilts/4.19/arm64/+/2110585

Change-Id: I87c74447c4d3dfe3767919edf5246129dc684fa0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>