Inventory variable is not being expanded during playbooks execution.

Issue

• Inventory variable which belongs to IP address of NFS server is not being expanded, despite of the installer creates the PVC the server object takes the literal content of the variable not expanded:

  $ grep -B2 netapp /etc/ansible/hosts
  #openshift_metrics_install_metrics=true
  openshift_metrics_storage_kind=nfs
  openshift_metrics_storage_host={{netapp}}
  --
  [OSEv3:vars]
  ## storage options
  netapp='test.local.lab'
  
  ###
  
  $ oc describe pv metrics-volume
  Name:            metrics-volume
  Labels:          storage=metrics
  Annotations:     <none>
  Finalizers:      [kubernetes.io/pv-protection]
  StorageClass:    
  Status:          Available
  Claim:           
  Reclaim Policy:  Retain
  Access Modes:    RWO
  Capacity:        10Gi
  Node Affinity:   <none>
  Message:         
  Source:
       Type:      NFS (an NFS mount that lasts the lifetime of a pod)
       Server:    {{netapp}} <<<<<<<<<<<<<<<<<
       Path:      /exports/metrics
       ReadOnly:  false
       Events:        <none>