Reland "Listen for feature state prefs."

This is a reland of commit c343f041110bbcdac7a16730005b30964eef24ab

The browsertests were failing in the `PRE_` part of the test because the some GM3 features are already enabled. The proposed fix is to only check if GM3 is enabled in the actual test.

Original change's description:
> Listen for feature state prefs.
>
> Change-Id: I366c7cacd4a66395463be7c3eb37320dbf699ed5
> Bug: b/303719523, b/310015636
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5018616
> Reviewed-by: Tarun Bansal <tbansal@chromium.org>
> Reviewed-by: Stefan Kuhne <skuhne@chromium.org>
> Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
> Reviewed-by: Tibor Goldschwendt <tiborg@chromium.org>
> Commit-Queue: Paul Adedeji <pauladedeji@google.com>
> Reviewed-by: Ryan Sultanem <rsult@google.com>
> Cr-Commit-Position: refs/heads/main@{#1227398}

Bug: b/303719523, b/310015636
Change-Id: I30149e13975e8ebc2be46e9d80ead8c3d2ccd17e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5054946
Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Reviewed-by: Stefan Kuhne <skuhne@chromium.org>
Reviewed-by: Tibor Goldschwendt <tiborg@chromium.org>
Commit-Queue: Paul Adedeji <pauladedeji@google.com>
Cr-Commit-Position: refs/heads/main@{#1228120}