Avoid sending unsupported counters to observers for now.
Avoid sending unsupported counters to observers for now.

These counters will be still be persisted in modb and
exported to prometheus

Signed-off-by: Tom Flynn <abc7c57a6537c493534eb3847500f37bef7b716d@gmail.com>
Change-Id: Ic3f7923c980feedd7637fe5c1e711f3ff2ad925f

opendaylight/opflex,opendaylight/opflex,opendaylight/opflex,opendaylight/opflex