Description of problem:

When redeploy metrics by re-run the metrics playbooks. The pvc name are changed from metrics-cassandra-1 to metrics-1. 

It may caused by the default value in openshift_facts/defaults/main.yml:openshift_metrics_storage_volume_name: 'metrics'


openshift_facts/defaults/main.yml:openshift_metrics_storage_volume_name: 'metrics'
openshift_metrics/defaults/main.yaml:openshift_metrics_cassandra_pvc_prefix: "{{ openshift_metrics_storage_volume_name | default('metrics-cassandra') }}"



Version-Release number of the following components:
openshift-ansible-3.9.0-0.31

How reproducible:
always

Steps to Reproduce:
1. Deploy Metrics with openshift-ansible-3.7.x 
2. Redeploy metrics with openshift-ansible-3.9.0-0.31
3. Check the pvc used by cassandra pod

# oc get pods hawkular-cassandra-1-jwn9b -o json |grep -A 1 persistentVolumeClaim
                "persistentVolumeClaim": {
                    "claimName": "metrics-1"

Actual results:
hawkular-cassandra pod changed the pvc from metrics-cassandra-1 to metrics-1.

[root@host-172-16-120-58 ~]# oc get pvc
NAME                  STATUS    VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
metrics-1             Bound     pvc-97d96125-0281-11e8-b8ae-fa163ee52e00   10Gi       RWO            standard       2d
metrics-cassandra-1   Bound     pvc-76a33773-0227-11e8-8e50-fa163ee52e00   10Gi       RWO            standard       2d


Expected results:
hawkular-cassandra pod should use the the prior metrics-cassandra-1

Additional info: