As these can otherwise block indefinitely due to docker issues.
This is to fix https://github.com/kubernetes/kubernetes/issues/53207,
where kubelet relies on cadvisor for gathering docker information as
part of its periodic node status update.
Cache the Docker thin pool name in the dockerFactory and pass it to each Docker container handler,
instead of calling `docker info` each time a new container handler is created, as the thin pool name
is extremely unlikely to change.
