Revert "[ios] Disables new content suggestions feed for eg tests."

This reverts commit 325c7e042b5141e5ab6a1c227aa3bccddd70c30b.

Reason for revert: Making AdvancedSettingsSigninTestCase and few other tests crash.
https://ci.chromium.org/ui/p/chrome/builders/ci/iphone-simulator/18722/overview

Original change's description:
> [ios] Disables new content suggestions feed for eg tests.
>
> Bug: 1178488
> Change-Id: Iae4755e81fc213552d2e77a859699410cbf348bd
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2698307
> Reviewed-by: Adam Trudeau-Arcaro <adamta@google.com>
> Commit-Queue: Sergio Collazos <sczs@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#854520}

Bug: 1178488
Change-Id: I7adbc34011a08612112381265fc4717da7794068
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2699887
Auto-Submit: Gauthier Ambard <gambard@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#854676}