Also add a plot group l4s. Usage: event_log_visualizer --plot=l4s filename |python3 Bug: webrtc:42225697 Change-Id: I5e1ee7028b9fb0707d5cabfe6d6f27c348e70a22 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/367199 Commit-Queue: Per Kjellander <perkj@webrtc.org> Reviewed-by: Björn Terelius <terelius@webrtc.org> Cr-Commit-Position: refs/heads/main@{#43416}