This adds a poll-and-timeout procedure after the pod is
started, to make sure the post-start hooks execute when the
container is actually running.
This is a temporal workaround for implementing post-hooks,
a long term solution is to use lifecycle event to trigger
those hooks, see https://github.com/kubernetes/kubernetes/issues/23084.
Also this fixes a bug of getting container ID for a non-running
container when running pre-stop hook.
Change all references to the container ID in pkg/kubelet/... to the
strong type defined in pkg/kubelet/container: ContainerID
The motivation for this change is to make the format of the ID
unambiguous, specifically whether or not it includes the runtime
prefix (e.g. "docker://").
David McMahon