Make hartmanng@ an OWNER of chrome/browser/webapps

BUG=None

Change-Id: I94099f04a98d4aac77764a78367e5db8b085cad2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2138251Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Reviewed-by: Glenn Hartmann <hartmanng@chromium.org>
Reviewed-by: Dominick Ng <dominickn@chromium.org>
Commit-Queue: Peter Kotwicz <pkotwicz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756890}

chrome/android/java/src/org/chromium/chrome/browser/webapps/OWNERS

 dominickn@chromium.org
+hartmanng@chromium.org
 mlamouri@chromium.org
 peconn@chromium.org
 peter@chromium.org