Specify Cinder Availability Zone in install-config.yaml

Issue

• In order to host RHOCP Nodes we need to add an AV zone in RHOSP. So the default value of 'nova' is replaced by 'My_AZ' using follwing stanzas in install-config.yaml

  controlPlane.platform.openstack.zones: ["My_AZ"]
  compute.platform.openstack.zones: ["My_AZ"]
  

But now the PVCs to the standard storage class in RHOCP are not working anymore.

    E0308 09:58:49.385897  1 goroutinemap.go:150] Operation for "my-amazing-project/amazing-pvc[7938ec83-51c9-47bd-b73b-bd2fc1791d10]" failed. No retries permitted until xxxx-03-08 x0:00:5y.38588187 +0000 UTC m=+24334.3322424 (durationBeforeRetry 2m2s). Error: "failed to create a 10 GB volume: Bad request with: 
    [POST: https://my.openstack.example:13776/v3/932jjdjdsj323332kj4kjjkkljl3abbeefb/volumes], error message: {\"badRequest\": {\"code\": 400, \"message\": \"Availability zone 'My_AZ' is invalid.\"}}"

• Cinder Availability Zone is still named "Nova".

• So please provide a config option in install-config.yaml to specifiy an alternative named cinder Availability Zone beside default of the Nova Availability Zone.