[IOS] Add mrefaat@ as owner to AppLauncher

I created all the files in the folder (some was moved around by others)
But i own all the logic inside all of them
Sample CLs:

Reason: 
https: //chromium-review.googlesource.com/c/chromium/src/+/727519/
https: //chromium-review.googlesource.com/c/chromium/src/+/1101497/
Change-Id: Id926cff97afbbe8097bf77e54bcb418e10be9ac4
Reviewed-on: https://chromium-review.googlesource.com/c/1487184
Commit-Queue: Mohammad Refaat <mrefaat@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#636533}

ios/chrome/browser/app_launcher/OWNERS

+mrefaat@chromium.org
+pkl@chromium.org
+
+# TEAM: ios-directory-owners@chromium.org
+# OS: iOS