Ensure gerrit admin's SSH key

Change-Id: Iddef0a5a9eb36a34373fcfa33d1656c879edb169
diff --git a/gerrit/client/init.yml b/gerrit/client/init.yml
index 0edd17e..7dd6c77 100644
--- a/gerrit/client/init.yml
+++ b/gerrit/client/init.yml
@@ -20,6 +20,10 @@
         protocol: http
         password: ${_param:gerrit_admin_password}
         key: ${_param:gerrit_admin_private_key}
+      user:
+        admin:
+          fullname: Administrator
+          ssh_key: ${_param:gerrit_admin_public_key}
       group:
         Event Streaming Users:
           description: Event Streaming Users