Bug 1907035 - fix about:support use of genai experiment strings, r=Mardak

Differential Revision: https://phabricator.services.mozilla.com/D216299

toolkit/content/aboutSupport.xhtml

@@ -30,6 +30,9 @@
     <link rel="localization" href="toolkit/global/processTypes.ftl"/>
 #ifndef ANDROID
     <link rel="localization" href="toolkit/featuregates/features.ftl"/>
+#if MOZ_BUILD_APP == browser
+    <link rel="localization" href="preview/genai.ftl" />
+#endif
 #endif
   </head>