Add dschinazi to //net OWNERS

As our team size shrinks again, it sounds preferable to have all
of our senior contributors in the OWNERS file.

R=eroman@chromium.org

Change-Id: I8edcc646809c5109b5427b3d952852ddcfd63f39
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2462463
Auto-Submit: David Schinazi <dschinazi@chromium.org>
Commit-Queue: Eric Roman <eroman@chromium.org>
Reviewed-by: Eric Roman <eroman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#815790}

net/OWNERS

 agl@chromium.org
 asanka@chromium.org
 davidben@chromium.org
+dschinazi@chromium.org
 ericorth@chromium.org
 eroman@chromium.org
 jkarlin@chromium.org