The value of the object tlsIgmpSnpgCfgMvrPolicy specifies
the policy statement that is applied to decide whether or not
a multicast group learned on a SAP with the object
sapIgmpSnpgCfgMvrFromVplsId set to this Tls can be joined to this Tls.
If an empty string is provided, all groups learned on these SAPs are
joined without applying a policy.