VPLS SAP statistics commands for 7210 SAS-D

config
    - service
        - vpls
        - no vpls
            - sap sap-id [split-horizon-group group-name] [eth-ring ring-index] [create]
            - no sap sap-id 
                - statistics
                    - egress
                        - [no] forwarded-count
                    - ingress
                        - counter-mode {in-out-profile-count | forward-drop-count}
                        - [no] received-count