Deny anonymous access to gerrit repos

PROD-31381

Change-Id: Ie4eeb1fb38ed749ed0450d7994c26323706f52ae
(cherry picked from commit 9a7d66dc150324d38fdcc231f0aada01f0592b57)
diff --git a/gerrit/client/init.yml b/gerrit/client/init.yml
index 16e4231..6a538b1 100644
--- a/gerrit/client/init.yml
+++ b/gerrit/client/init.yml
@@ -39,6 +39,9 @@
           actions:
           - name: read
             group: Non-Interactive Users
+          - name: read
+            group: Anonymous Users
+            deny: true
         "refs/heads/*":
           actions:
           - name: abandon