CMO may generate Kubernetes events with a wrong object reference

When CMO restarts after all monitoring components are deployed, the event recorder would use the alertmanager-main statefulset as the object's reference in events.

4.11

Always

1. Deploy a cluster
2. Delete the openshift-monitoring/metrics-client-certs secret 
3. oc get events -n openshift-monitoring

Events about certificate generation are related to statefulset/alertmanager-main

Events should be related to deployment/cluster-monitoring-operator