support multiple links by in APBR Midstream logs
support multiple links by in APBR Midstream logs

handle APBR Midstream structured syslog messages
which now has bytes info for multiple interfaces used
for the session

Change-Id: I8ba8ff76b5b55e7c6e72aaa956aed9d3eaacf41a
Closes-Bug: #1719563

rombie/contrail-controller,eonpatapon/contrail-controller,eonpatapon/contrail-controller,rombie/contrail-controller,nischalsheth/contrail-controller,eonpatapon/contrail-controller,nischalsheth/contrail-controller,rombie/contrail-controller,eonpatapon/contrail-controller,eonpatapon/contrail-controller,rombie/contrail-controller,rombie/contrail-controller,nischalsheth/contrail-controller,nischalsheth/contrail-controller,nischalsheth/contrail-controller,rombie/contrail-controller,nischalsheth/contrail-controller,eonpatapon/contrail-controller,nischalsheth/contrail-controller,rombie/contrail-controller,eonpatapon/contrail-controller,nischalsheth/contrail-controller