portage-stable: Add Killmode=process into openssh service

By default, sshd's KillMode is control-group. Whenever, we reboot
the sshd, it will restart main daemon and forked processes, which
results to the drop of current sessions. This is not desired behavior
from customers, and also results to confusion and problem in the bug.

Other Enterprise distribution perfers to limit the killmode at process
level, which makes sens in a lot of scenarios.

BUG=b/176502144, b/176940335
TEST=presbumit, and manually test(systemctl restart sshd)
RELEASE_NOTE=None

cos-patch: bug
Change-Id: Id460b735d016edbfbd26dd23a651d91df863c9ca
Reviewed-on: https://cos-review.googlesource.com/c/third_party/overlays/portage-stable/+/15970
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Robert Kolchmeyer <rkolchmeyer@google.com>
(cherry picked from commit d233351840202e0df84cd80fe1490db04b55948f)
Reviewed-on: https://cos-review.googlesource.com/c/third_party/overlays/portage-stable/+/15971
Main-Branch-Verified: Roy Yang <royyang@google.com>
1 file changed