Make kNewGetDisplayMediaPickerOrder default-disabled

Instead of shipping to 100%, we will run an experiment.

Bug: 1358278
Change-Id: Ia0d234437a993a03d274d9909e3271a95c0704ca
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3882930


Auto-Submit: Elad Alon <eladalon@chromium.org>
Commit-Queue: Fr <beaufort.francois@gmail.com>
Reviewed-by: Fr <beaufort.francois@gmail.com>
Cr-Commit-Position: refs/heads/main@{#1044510}