The very verbose logging was making the unit test output too much.
Disable verbose logging by default.

Bug: angleproject:3162
Change-Id: I1b675877c314573749c9808684bab0c60f7d6127
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1821937Reviewed-by: Ian Elliott <ianelliott@google.com>
Commit-Queue: Jamie Madill <jmadill@chromium.org>