Change event service implementation to use containerd event service

[richardcase]

Describe the solution you'd like:
The event bus implementation should be the containerd event service.

Why do you want this feature:
Instead of using a separate event bus we should use the containerd event service as it will make it easier responding to existing containerd events and we already are using contaierd for a bunch of other things.

Anything else you would like to add:
[Miscellaneous information that will assist in solving the issue.]