client-go: use klog.V(3) for the cert-rotation controller start/stop
client-go: use klog.V(3) for the cert-rotation controller start/stop

Introduce a verbosity level for the start and stop notifications,
so that regular calls to commands such as:
  "kubectl auth ..."
would only contain the "yes" / "no" output.

Kubernetes-commit: b2677b1e572ae1cd8b823683e88005b7857d8938

li-ang/client-go,kubernetes/client-go