Neutron-ovs-agent can now enable IGMP snooping in integration bridge
if config option "igmp_snooping_enable" in OVS section in config will
be set to True.
It will also set mcast-snooping-disable-flood-unregistered=true
so flooding of multicast packets to all unregistered ports will be
disabled also.
Both changes are applied on integration bridge.
Change-Id: I12f4030a35d10d1715d3b4bfb3ed5efb9aa28f2b
Closes-Bug: #1840136
(cherry picked from commit 5b341150e2)
b5d67929b7