src/test: use stage tests for prod-beta tests

Content sources is now available in prod-beta, so let's test simulating
the production env, but split on beta/non-beta.

src/test/Components/CreateImageWizard/CreateImageWizard.test.js

@@ -162,7 +162,7 @@ beforeAll(() => {
         },
       },
       isBeta: () => {
-        return true;
+        return false;
       },
       isProd: () => {
         return true;