Disabling cluster UWM requires manual pruning of ACM observability UWL deployment

Description of problem:

When UWM is enabled, and then disabled, ACM Obs addon reports Cluster metrics sent successfully ; User Workload: Failed to retrieve metrics

Version-Release number of selected component (if applicable):

2.7.3

How reproducible:

100%

Steps to Reproduce:

1. Enable UWM on the cluster: https://docs.openshift.com/container-platform/4.12/monitoring/enabling-monitoring-for-user-defined-projects.html
2. Setup ACM Obs.  Verify that a pod named uwl-metircs-collector-xxxx  exists in open-cluster-management-addon-observability namespace.
3. Disable UWM on the cluster

Actual results:

• ACM observability-controller addon reports Cluster metrics sent successfully ; User Workload: Failed to retrieve metrics
• Pod named uwl-metircs-collector-xxxx  still exists in open-cluster-management-addon-observability namespace

Expected results:

• ACM observability-controller addon should report Available

Additional info: