Introduce test case name for proper metrics reporting across different parts of framework. Bug: webrtc:10138 Change-Id: I7c501413ca2f2ee40314d988855dec0c28381c47 Reviewed-on: https://webrtc-review.googlesource.com/c/124740 Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org> Commit-Queue: Artem Titov <titovartem@webrtc.org> Cr-Commit-Position: refs/heads/master@{#26886}