Add more Gatekeeper OWNERS

Test: none
Change-Id: I3bbe76b0d9cfd9eddc53301566e1761d0a3876e2
diff --git a/gatekeeper/OWNERS b/gatekeeper/OWNERS
index fddc2ff..5262dce 100644
--- a/gatekeeper/OWNERS
+++ b/gatekeeper/OWNERS
@@ -1,4 +1,6 @@
 # Bug component: 1124862
-swillden@google.com
+drysdale@google.com
 guangzhu@google.com
+oarbildo@google.com
 subrahmanyaman@google.com
+swillden@google.com