Update Cilium agent module to support L4 rules

Implementation plan:

• Based on what has been done in #277156 (closed)

Related code: Flow related: https://github.com/cilium/cilium/blob/v1.8/api/v1/flow/flow.pb.go#L277 Rules related: https://github.com/cilium/cilium/blob/v1.8/pkg/policy/api/ingress.go#L69 and https://github.com/cilium/cilium/blob/v1.8/pkg/policy/api/egress.go#L71