Add networks stats collector from PeerConnection GetStats API for.
PeerConnection level test framework. It also will log network layer
stats for debug purposes and report packets/bytes dropped metrics from
network layer to monitor connectivity of network layer.
Bug: webrtc:11756
Change-Id: I899c94e4708654a01e78ffa93fb5c88a521c93c2
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/180804
Reviewed-by: Andrey Logvin <landrey@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31845}
b54ef11042