Router readiness probe failed due to kubelet cannot find router healthz endpoint.
This is caused that the healthz endpoint is added only when there is any update request
send to the updateRouterRequestChannel, and makes router failed.
This PR sends an update request right before the router is started to avoid the problem.
This PR removes not so useful logs and changes most of Info level
log to Debug/Error level in hot path while preserving some of them
that is helpful for troubleshooting.
