Updates GCP CredentialsRequest

- Adds compute.images.useReadOnly

Author: theobarberbany

install/0000_30_machine-api-operator_00_credentials-request.yaml

@@ -172,6 +172,7 @@ spec:
     - "compute.healthChecks.useReadOnly"
     - "compute.images.get"
     - "compute.images.getFromFamily"
+    - "compute.images.useReadOnly"
     - "compute.instanceGroups.create"
     - "compute.instanceGroups.delete"
     - "compute.instanceGroups.get"