Add eladalon@ as hangout services extension owner.

Bug: None
Change-Id: I7668ba3ac3c13bbf6139d5110eb842342c8a7caa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1826657Reviewed-by: Elad Alon <eladalon@chromium.org>
Commit-Queue: Henrik Grunell <grunell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#700194}

chrome/browser/resources/hangout_services/OWNERS

-bemasc@chromium.org
+eladalon@chromium.org
 grunell@chromium.org