Operator fails with node group XX has volume claim template without storage class which is not allowed

[cintoSunny]

The operator fails with node group historical has volume claim template without storage class which is not allowed
This is because there is no storageClassName in the Volume Claim Templates. This is the exact check

druid-operator/controllers/druid/volume_expansion.go

Line 28 in 94f8ee8

func validateNodeVolumeClaimTemplateSpec(nodeSpec *v1alpha1.DruidNodeSpec) error {

func validateNodeVolumeClaimTemplateSpec(nodeSpec *v1alpha1.DruidNodeSpec) error {
	for _, vct := range nodeSpec.VolumeClaimTemplates {
		if vct.Spec.StorageClassName == nil || *vct.Spec.StorageClassName == "" {
			return fmt.Errorf("node group %s has volume claim template without storage class which is not allowed: %s",
				nodeSpec.NodeType, vct.Name)
		}
	}
	return nil
}

This was recently added, and hence existing runs are failing that doesn't have this field - StorageClassName. Is there any particular reason we added this? I mean, apart from volumeExpansion do we need it anywhere? I can change the code accordingly.