Trace Tests: Add renderer string logging. This outputs the GL_RENDERER string in each test when using the --verbose-logging command-line flag. Bug: b/173518650 Change-Id: Id966294d50aaba0c8a1f3e010f76d5560e6f1288 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2545403 Reviewed-by: Charlie Lao <cclao@google.com> Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com> Commit-Queue: Jamie Madill <jmadill@chromium.org>