Set security group provider rule for icmpv6 RA in DVR

Set security group provider rule for icmpv6 RA in DVR

Security group provider rules for RA is set for the VM ports
when a router interface is added or updated after the VM
instance is created.

In the case of DVR Routers the security group provider rule
to allow the RA packets to flow through the VM port input
chain was missing and so the VM was not able to get a
SLAAC/DHCP address when associated with a DVR Router.

This fix will add the security group rule to the VM port input
chain to allow the RA packets to flow into the VM and hence
the VM will obtain an IP address assigned by the Router.

Closes-Bug: #1501969

Change-Id: Ib0b3499d9c880fe1462734b2d4092debf4819509