[iOS] Add jlebel@ and fernandex@ as OWNERS of the Settings screens.

As a part of various projects including the Sign-in architecture
migration, account list management, and exploratory prototypes of MICe
these reviewers have become very familiar with the Settings
codebase and would like to take additional responsibility in its upkeep
and future changes.

Bug: 971989
Change-Id: I423c6f1ca6f5df50297054e71c40f5e2a5b96e2d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2198967Reviewed-by: Mark Cogan <marq@chromium.org>
Commit-Queue: Nohemi Fernandez <fernandex@chromium.org>
Cr-Commit-Position: refs/heads/master@{#768805}

ios/chrome/browser/ui/settings/OWNERS

@@ -2,6 +2,8 @@ edchin@chromium.org
 sczs@chromium.org
 sdefresne@chromium.org
 gambard@chromium.org
+jlebel@chromium.org
+fernandex@chromium.org
 
 # TEAM: ios-directory-owners@chromium.org
 # OS: iOS