Reland "Remove feature parameters in favor of grit strings."

This reverts commit e79a77f9ee7edfdfd3fb392bcf44e5bb903ac879.

The test failures appear to have been caused by iOS eg tests that
relied on setting the suggestion string via the feature parameter.
In the mean time, these tests were disabled by gardeners:
https://chromium-review.googlesource.com/c/chromium/src/+/5348961

This CL relands the original change and will then follow up by fixing
and re-enabling the iOS eg tests.

Original change's description:
> Revert "Remove feature parameters in favor of grit strings."
>
> This reverts commit ca85f83f8fb1e33cd04da057a7d950e213135ed9.
>
> Reason for revert: Breaking tests on ios waterfall https://ci.chromium.org/ui/p/chromium/builders/ci/ios-simulator-full-configs/54136/overview
>
> Original change's description:
> > Remove feature parameters in favor of grit strings.
> >
> > There is no need for feature parameters to set UI strings, as those can
> > be set directly in the finch config.
> >
> > Bug: 327716672
> > Change-Id: If4ec85301c97da882d212b4fb6e013aafd94a3b6
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5335343
> > Commit-Queue: Jan Keitel <jkeitel@google.com>
> > Reviewed-by: Colin Blundell <blundell@chromium.org>
> > Reviewed-by: Dana Fried <dfried@chromium.org>
> > Reviewed-by: Bruno Braga <brunobraga@google.com>
> > Cr-Commit-Position: refs/heads/main@{#1269162}
>
> Bug: 327716672
> Change-Id: Iccb1a6cf3477266af958442bcfa5fa8348b3e470
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5350880
> Commit-Queue: Chris Lu <thegreenfrog@chromium.org>
> Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
> Reviewed-by: Sergio Collazos <sczs@chromium.org>
> Auto-Submit: Chris Lu <thegreenfrog@chromium.org>
> Owners-Override: Chris Lu <thegreenfrog@google.com>
> Cr-Commit-Position: refs/heads/main@{#1269390}

Bug: 327716672
Change-Id: I115787636acd38bacc12c021e7c63bacc6a564c0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5349291
Reviewed-by: Colin Blundell <blundell@chromium.org>
Commit-Queue: Jan Keitel <jkeitel@google.com>
Reviewed-by: Dana Fried <dfried@chromium.org>
Reviewed-by: Bruno Braga <brunobraga@google.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#1269674}