flags: assign extension-apis

Per email discussion :)

Bug: None
Change-Id: I92886849f0c29ac70b3743b777844a188914bc94
Reviewed-on: https://chromium-review.googlesource.com/c/1496918
Auto-Submit: Elly Fong-Jones <ellyjones@chromium.org>
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#636863}

chrome/browser/flag-metadata.json

@@ -2057,7 +2057,7 @@
   },
   {
     "name": "extension-apis",
-    // "owners": [ "your-team" ],
+    "owners": [ "rdevlin.cronin" ],
     "expiry_milestone": 76
   },
   {