[AWS][ELB LOGS] [NLB Access logs] Support for ALPN Policy

[agithomas]

The details of the NLB Access log can be found here

Creating this issue for the following purposes

1. Support for ALPN policy. This involves parsing the following fields alpn_fe_protocol, alpn_be_protocol, alpn_client_preference_list, tls_connection_creation_time from the logs and storing the parsed field values.

2. Support for the following log patterntls 2.0 2020-04-01T08:51:42 net/my-network-loadbalancer/c6e77e28c25b2234 g3d4b5e8bb8464cd 72.21.218.154:51341 172.100.100.185:443 5 2 98 246 - arn:aws:acm:us-east-2:671290407336:certificate/2a108f19-aded-46b0-8493-c63eb1ef4a99 - ECDHE-RSA-AES128-SHA tlsv12 - my-network-loadbalancer-c6e77e28c25b2234.elb.us-east-2.amazonaws.com h2 h2 "h2","http/1.1" 2020-04-01T08:51:20, allowing empty values for aws.elb.connection_time.ms and aws.elb.tls_handshake_time.ms

[agithomas]

PR is created to fix the above-mentioned issues. #11590.