---
openshift_storageclass_defaults:
  aws:
    name: gp2
    provisioner: kubernetes.io/aws-ebs
    type: gp2
  gcp:
    name: standard
    provisioner: kubernetes.io/gce-pd
    type: pd-standard

openshift_storageclass_name: "{{ openshift_storageclass_defaults[openshift_cloudprovider_kind]['name'] }}"
openshift_storageclass_provisioner: "{{ openshift_storageclass_defaults[openshift_cloudprovider_kind]['provisioner'] }}"
openshift_storageclass_type: "{{ openshift_storageclass_defaults[openshift_cloudprovider_kind]['type'] }}"

---
openshift_storageclass_defaults:
  aws:
    name: gp2
    provisioner: kubernetes.io/aws-ebs
    type: gp2
  gce:
    name: standard
    provisioner: kubernetes.io/gce-pd
    type: pd-standard

openshift_storageclass_name: "{{ openshift_storageclass_defaults[openshift_cloudprovider_kind]['name'] }}"
openshift_storageclass_provisioner: "{{ openshift_storageclass_defaults[openshift_cloudprovider_kind]['provisioner'] }}"
openshift_storageclass_type: "{{ openshift_storageclass_defaults[openshift_cloudprovider_kind]['type'] }}"

Change default key for gce
Change default key for gce

The usual convention is to use gce not gcp
