Terry Wilson researched the option to backport this feature and mentioned it requires a DB migration in addition to code conflicts -
" Even just the main patch has lots of conflicts, including some db migration stuff, would probably be pretty messy
Unmerged paths:
(use "git add/rm <file>..." as appropriate to mark resolution)
deleted by us: neutron/agent/linux/iptables_comments.py
both modified: neutron/agent/linux/iptables_firewall.py
both modified: neutron/db/migration/alembic_migrations/versions/HEAD
both modified: neutron/db/portsecurity_db.py
both modified: neutron/plugins/ml2/plugin.py
deleted by us: neutron/tests/functional/agent/linux/test_iptables_firewall.py
both modified: neutron/tests/unit/test_iptables_firewall.py
both modified: setup.cfg
"