feat(i18n): expand supported languages

lib/l10n/gen/app_localizations.dart

@@ -5,8 +5,19 @@ import 'package:flutter/widgets.dart';
 import 'package:flutter_localizations/flutter_localizations.dart';
 import 'package:intl/intl.dart' as intl;
 
+import 'app_localizations_ar.dart';
+import 'app_localizations_bn.dart';
+import 'app_localizations_de.dart';
 import 'app_localizations_en.dart';
 import 'app_localizations_es.dart';
+import 'app_localizations_fr.dart';
+import 'app_localizations_hi.dart';
+import 'app_localizations_id.dart';
+import 'app_localizations_it.dart';
+import 'app_localizations_ja.dart';
+import 'app_localizations_pt.dart';
+import 'app_localizations_ru.dart';
+import 'app_localizations_zh.dart';
 
 // ignore_for_file: type=lint
 
@@ -94,8 +105,19 @@ abstract class AppLocalizations {
 
   /// A list of this localizations delegate's supported locales.
   static const List<Locale> supportedLocales = <Locale>[
+    Locale('ar'),
+    Locale('bn'),
+    Locale('de'),
     Locale('en'),
     Locale('es'),
+    Locale('fr'),
+    Locale('hi'),
+    Locale('id'),
+    Locale('it'),
+    Locale('ja'),
+    Locale('pt'),
+    Locale('ru'),
+    Locale('zh'),
   ];
 
   /// No description provided for @appTitle.
@@ -679,8 +701,21 @@ class _AppLocalizationsDelegate
   }
 
   @override
-  bool isSupported(Locale locale) =>
-      <String>['en', 'es'].contains(locale.languageCode);
+  bool isSupported(Locale locale) => <String>[
+    'ar',
+    'bn',
+    'de',
+    'en',
+    'es',
+    'fr',
+    'hi',
+    'id',
+    'it',
+    'ja',
+    'pt',
+    'ru',
+    'zh',
+  ].contains(locale.languageCode);
 
   @override
   bool shouldReload(_AppLocalizationsDelegate old) => false;
@@ -689,10 +724,32 @@ class _AppLocalizationsDelegate
 AppLocalizations lookupAppLocalizations(Locale locale) {
   // Lookup logic when only language code is specified.
   switch (locale.languageCode) {
+    case 'ar':
+      return AppLocalizationsAr();
+    case 'bn':
+      return AppLocalizationsBn();
+    case 'de':
+      return AppLocalizationsDe();
     case 'en':
       return AppLocalizationsEn();
     case 'es':
       return AppLocalizationsEs();
+    case 'fr':
+      return AppLocalizationsFr();
+    case 'hi':
+      return AppLocalizationsHi();
+    case 'id':
+      return AppLocalizationsId();
+    case 'it':
+      return AppLocalizationsIt();
+    case 'ja':
+      return AppLocalizationsJa();
+    case 'pt':
+      return AppLocalizationsPt();
+    case 'ru':
+      return AppLocalizationsRu();
+    case 'zh':
+      return AppLocalizationsZh();
   }
 
   throw FlutterError(