Updates GCP credentials request

This change adds the compute.images.get and getFromFamily to the
credentials request for GCP. It is required by MAPG for checking if a
disk is UEFI compatible.

See openshift/machine-api-provider-gcp#108

Author: theobarberbany

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

@@ -174,6 +174,8 @@ spec:
     - "compute.globalOperations.get"
     - "compute.globalOperations.list"
     - "compute.healthChecks.useReadOnly"
+    - "compute.images.get"
+    - "compute.images.getFromFamily"
     - "compute.instanceGroups.create"
     - "compute.instanceGroups.delete"
     - "compute.instanceGroups.get"