Description of problem:
with the recent introduced as part of the bug fix [1] and due to this inventory file parameters for configuring metrics has to be changed as below otherwise pvc will always be in pending state and customer / user will see the error below.

Type    Reason         Age                From                         Message
  ----    ------         ----               ----                         -------
  Normal  FailedBinding  3m (x908 over 3h)  persistentvolume-controller  no persistent volumes available for this claim and no storage class is set


[1] https://github.com/openshift/openshift-ansible/pull/11586#issuecomment-512073674

# metrics
openshift_metrics_install_metrics=true
openshift_metrics_cassandra_storage_type=pv
openshift_metrics_hawkular_nodeselector={"node-role.kubernetes.io/infra": "true"}
openshift_metrics_cassandra_nodeselector={"node-role.kubernetes.io/infra": "true"}
openshift_metrics_heapster_nodeselector={"node-role.kubernetes.io/infra": "true"}
openshift_metrics_storage_volume_size=20Gi
openshift_metrics_cassandra_pvc_storage_class_name="glusterfs-registry-block"


Version-Release number of selected component (if applicable):
OCS3.11

How reproducible:
Always

Steps to Reproduce:
1. Use -   openshift-ansible-3.11.123-1.git.0.11838de.el7.noarch.rpm to install metrics with old inventory file as suggested in the doc.
2.
3.

Actual results:
pvc for metrics does not get bounded.

Expected results:
pvc for metrics should get bounded.

Additional info: