Add variable for the vsphere-csi namespace (#9278)

docs/vsphere-csi.md

roles/kubernetes-apps/csi_driver/vsphere/defaults/main.yml

roles/kubernetes-apps/csi_driver/vsphere/tasks/main.yml

...er/vsphere/templates/vsphere-csi-controller-config.yml.j2

...sphere/templates/vsphere-csi-controller-deployment.yml.j2

...iver/vsphere/templates/vsphere-csi-controller-rbac.yml.j2

...r/vsphere/templates/vsphere-csi-controller-service.yml.j2

...csi_driver/vsphere/templates/vsphere-csi-namespace.yml.j2

...csi_driver/vsphere/templates/vsphere-csi-node-rbac.yml.j2

...apps/csi_driver/vsphere/templates/vsphere-csi-node.yml.j2