🐻 [Pandora] Plugging the new FRE UI behind a flag

Plugging the new FRE UI to the SceneController behind a flag.

Demo: https://drive.google.com/file/d/1hMO04a5JEq2TtQUDkFiJmy2kFBardr24/view?usp=sharing

Bug: 1189807
Change-Id: I8ba897bf22488e99920e712019fe6e07ff59141c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2842496
Commit-Queue: Tina Wang <tinazwang@chromium.org>
Reviewed-by: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#875251}
GitOrigin-RevId: 6e94a471e9662e8bfc59178f1f7b78c262605044
6 files changed