Before if there is no video in PC quality test video quaity analyzer
failed on RTC_CHECK becuase of empty counter. Now it will report no
metrics and print 0 in debug logging.
Bug: webrtc:10138
Change-Id: If6656a613465c522cac1d4b2e4dd455e409229ba
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/133886
Reviewed-by: Artem Titarenko <artit@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27731}