Update kernel to builds 8840540 am: 0270554915 am: 5256ebffd1

Original change: https://googleplex-android-review.googlesource.com/c/kernel/prebuilts/5.15/arm64/+/19320907

Change-Id: If2e5968ebb092864f54448badad933f773d97d91
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>