allow empty storageClassNames

{{cookiecutter.project_slug}}/templates/{{cookiecutter.template_base_name}}/persistentvolumeclaims.yaml

@@ -42,7 +42,15 @@ spec:
   {{- if $options.volumeName }}
   volumeName: {{ $options.volumeName | quote }}
   {{- end }}
-  storageClassName: {{ $options.storageClassName | default "ocs-storagecluster-cephfs" | quote }}
+  {{- if kindIs "invalid" $options.storageClassName -}}
+  {{- /*
+  We do allow empty storageClassNames here (i.e. ""). but if it is not defined, 
+  we use "ocs-storagecluster-cephfs".
+  */}}
+  storageClassName: "ocs-storagecluster-cephfs"
+  {{- else }}
+  storageClassName: {{ $options.storageClassName | quote }}
+  {{- end }}
   {%- endraw %}
 ...
 {%- raw %}