Update OWNERS to reflect team changes (#40358)

add Dima, remove folks no longer on team

Author: jpettitt

extensions/amp-subscriptions-google/OWNERS

@@ -5,10 +5,8 @@
   rules: [
     {
       owners: [
-        {name: 'alin04'},
         {name: 'chrisantaki'},
-        {name: 'fikus'},
-        {name: 'hartmannr76'},
+        {name: 'dkravchuk'},
         {name: 'jpettitt', notify: true},
       ],
     },