Resolve experiment name issues for new_create_project_ui

- we were using feature flag checking on experiment name
  instead of feature flag name that has the suffix.

app/assets/javascripts/pages/projects/new/index.js

@@ -3,13 +3,14 @@ import initProjectNew from '../../../projects/project_new';
 import { __ } from '~/locale';
 import { deprecatedCreateFlash as createFlash } from '~/flash';
 import Tracking from '~/tracking';
+import { isExperimentEnabled } from '~/lib/utils/experimentation';
 
 document.addEventListener('DOMContentLoaded', () => {
   initProjectVisibilitySelector();
   initProjectNew.bindEvents();
 
   const { category, property } = gon.tracking_data ?? { category: 'projects:new' };
-  const hasNewCreateProjectUi = 'newCreateProjectUi' in gon?.features;
+  const hasNewCreateProjectUi = isExperimentEnabled('newCreateProjectUi');
 
   if (!hasNewCreateProjectUi) {
     // Setting additional tracking for HAML template

app/controllers/projects_controller.rb

@@ -37,7 +37,7 @@ class ProjectsController < Projects::ApplicationController
   # Experiments
   before_action only: [:new, :create] do
     frontend_experimentation_tracking_data(:new_create_project_ui, 'click_tab')
-    push_frontend_feature_flag(:new_create_project_ui) if experiment_enabled?(:new_create_project_ui)
+    push_frontend_experiment(:new_create_project_ui)
   end
 
   before_action only: [:edit] do