LTS Refresh: Merge upto 51d5c624a0a37c8501fb3a2ed66f0a2dee6ac48a (buildnumber: 18867.294.0) from main-R121-cos-6.6 to release-R121-cos-6.6.

BUG=b/452354250
TEST=presubmit
RELEASE_NOTE=LTS Refresh from main-R121-cos-6.6 to release-R121-cos-6.6

Change-Id: Ib2d7f9b5e455f7584c550dc6ed760818d35a9e81
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/115025
Reviewed-by: He Gao <hegao@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>