[iOS][Safety Check] Add Safety Check UI OWNERS

Add harrisonsean and javierrobles as owners to the
safety check UI code on iOS .

Bug: 1078780
Change-Id: Ifbe9e38c88e6bb0dfe9604c1e1a01b9fec4e58b9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2375245Reviewed-by: Sergio Collazos <sczs@chromium.org>
Reviewed-by: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Commit-Queue: Sean Harrison <harrisonsean@chromium.org>
Cr-Commit-Position: refs/heads/master@{#801353}

ios/chrome/browser/ui/settings/safety_check/OWNERS

+harrisonsean@chromium.org
+javierrobles@chromium.org
+
+# TEAM: ios-directory-owners@chromium.org
+# OS: iOS