✨ feat: default to user-selected country when fetching content bundles, fall back to locale country (#1284)

Author: hspinks

client/flutter/lib/api/content/content_loading.dart

@@ -1,5 +1,6 @@
 import 'dart:io';
 import 'package:who_app/api/endpoints.dart';
+import 'package:who_app/api/user_preferences.dart';
 import 'package:who_app/api/who_service.dart';
 import 'package:flutter/services.dart' show rootBundle;
 import 'package:flutter/cupertino.dart';
@@ -27,7 +28,8 @@ class ContentLoading {
   /// to a local asset.  If no bundle can be found with the specified name an exception is thrown.
   Future<ContentBundle> load(Locale locale, String name) async {
     var languageCode = locale.languageCode;
-    var countryCode = locale.countryCode;
+    var countryCode =
+        (await UserPreferences().getCountryIsoCode()) ?? locale.countryCode;
     var languageAndCountry = "${languageCode}_${countryCode}";
     var unsupportedSchemaVersionAvailable = false;