Install all plugins

Change-Id: I2391f5910d47e2b37d7ac5493fd8c40c06eafa42
diff --git a/gerrit@3.11.0.rb b/gerrit@3.11.0.rb
index e3fa531..ceb730b 100644
--- a/gerrit@3.11.0.rb
+++ b/gerrit@3.11.0.rb
@@ -22,6 +22,6 @@
     (prefix/"plugins").install "plugins/uploadvalidator.jar"
     (prefix/"plugins").install "plugins/avatars-gravatar.jar"
 
-    system "java", "-jar", bin/"gerrit.war", "init", "-d", prefix, "--batch"
+    system "java", "-jar", bin/"gerrit.war", "init", "-d", prefix, "--batch", "--install-all-plugins"
   end
 end