Li Migration: barrier=true does not seem to be sending a barrier message

We are adding flow to MD-SAL data store (FRM) with barrier=true for the flows. Analyzing the OF packet flow to the switch, we do not see the barrier request/reply being sent out to the switch.

To reproduce, start mininet, add a flow with the barrier attribute set to true and observe the OF Protocol to the switch. Barrier message will not be sent.

Note that the Li plugin sends out a lot of barriers, but not when asked by the user to send one before / after a flow that the user wants to synchronize.