Eventing debugging example points to non-existing message_dumper image

[tplevko]

Expected Behavior

The example describing debugging of eventing component should contain example.yaml pointing to correct image. Specifically the message_dumper seems not to exist.

Steps to Reproduce the Problem

1. Follow the steps in example.yaml
2. When instructed to apply example.yaml - the problem can be observed on the cluster.

Install information:

• Platform (GKE, IKS, AKS, etc.): AWS
• Knative Version: OpenShift 4.7

[grantr]

Message_dumper was replaced by event_display. Probably just needs an update to gcr.io/knative-releases/knative.dev/eventing-sources/cmd/event_display