integrate kubelet with the systemd watchdog

[SergeyKanzhelev]

Implement the systemd watchdog in kubelet. Similar to containerd/containerd#10329, we want to have a lightweight way to health check kubelet instead of requiring to run the health check process curl-ing the /healthz endpoint.

Implementation will require integrating with watchdog API, hooking those with the same checks that /healthz performs, and implement some e2e_node tests demonstrating this behavior. Documentation should be updated once implemented as well.

/sig node
/area kubelet
/kind feature

/good-first-issue
/help

[SergeyKanzhelev]

/priority backlog
/triage accepted

[RocooHash]

I can give this a shot

/assign

[yunzck8s]

I want to try it too

/assign

[ajit97singh]

I want to try it too

/assign