Fix monit configs for neutron services

After the quantum to neutron rename in Havanna, the monitoring recipes
were still using quantum in the logic/attributes, causing monit to not
monitor the ls, dhcp, metadata, and ovs bits.

- Update dhcp/l3/metadata agent monitoring to use neutron instead of
  quantum
- update ovs plugin agent monitoring to use neutron instead of quamtum

Issue rcbops/chef-cookbooks#914