Update fieldtrial_testing_config to reflect new study name

Change-Id: Ic97424b793c1b6b694b73548754099ea0938a435
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5800257


Reviewed-by: Friedrich Horschig <fhorschig@chromium.org>
Commit-Queue: Nick Birnie <birnie@google.com>
Cr-Commit-Position: refs/heads/main@{#1344915}