Update test to reflect new default defer behavior for generated component packs

Author: AbanoubGhadban

spec/dummy/spec/helpers/react_on_rails_helper_spec.rb

@@ -50,7 +50,7 @@ class PlainReactOnRailsHelper
       allow(helper).to receive(:append_javascript_pack_tag)
       allow(helper).to receive(:append_stylesheet_pack_tag)
       expect { helper.load_pack_for_generated_component("component_name", render_options) }.not_to raise_error
-      expect(helper).to have_received(:append_javascript_pack_tag).with("generated/component_name", { defer: true })
+      expect(helper).to have_received(:append_javascript_pack_tag).with("generated/component_name", { defer: false })
       expect(helper).to have_received(:append_stylesheet_pack_tag).with("generated/component_name")
     end