Add "Gi" after size value for registry, metrics, and logging

[netzzer]

Specifying the unit appears to be important. Current behavior:

- openshift_hosted_registry_storage_volume_size=20
- openshift_metrics_storage_volume_size=25
- openshift_logging_es_pvc_size=25

Desired output:

+ openshift_hosted_registry_storage_volume_size=20Gi
+ openshift_metrics_storage_volume_size=25Gi
+ openshift_logging_es_pvc_size=25Gi

[netzzer]

Fixed with PR#17