CrOS Settings: Enable the Settings revamp feature flag by default

Enables the OsSettingsRevampWayfinding feature flag by default and
removes the corresponding field trial test config entry.

Bug: b/325649023
Test: browser_tests --gtest_filter="OSSettings*"
Change-Id: Ic19553cf11acf5f8460f101c6e35d60762f18020
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5303999


Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Commit-Queue: Wes Okuhara <wesokuhara@google.com>
Cr-Commit-Position: refs/heads/main@{#1261879}