Bug 1886769 - Add search widget installed custom attribute. r=android-reviewers,mcarare,amejiamarmol

Differential Revision: https://phabricator.services.mozilla.com/D205337

app/src/main/java/org/mozilla/fenix/messaging/CustomAttributeProvider.kt

@@ -79,6 +79,8 @@ object CustomAttributeProvider : JexlAttributeProvider {
 
                 "are_notifications_enabled" to NotificationManagerCompat.from(context)
                     .areNotificationsEnabledSafe(),
+
+                "search_widget_is_installed" to settings.searchWidgetInstalled,
             ),
         )
     }