Temporary workaround to avoid the same variant name for multiple
variants of the same test.

Bug: v8:6917
Change-Id: I9a25dcaf81d35da0dc2617c089cb4811c2a958cb
Cq-Include-Trybots: luci.v8.try:v8_linux64_fyi_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/852833
Commit-Queue: Michał Majewski <majeski@google.com>
Reviewed-by: Sergiy Byelozyorov <sergiyb@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50428}