Default to en as fallBack and hardcode supported locales

lib/app.dart

@@ -10,6 +10,7 @@ import 'package:logging/logging.dart';
 import 'package:media_extension/media_extension_action_types.dart';
 import 'package:photos/ente_theme_data.dart';
 import "package:photos/generated/l10n.dart";
+import "package:photos/l10n/l10n.dart";
 import 'package:photos/services/app_lifecycle_service.dart';
 import 'package:photos/services/sync_service.dart';
 import 'package:photos/ui/home_widget.dart';
@@ -71,7 +72,8 @@ class _EnteAppState extends State<EnteApp> with WidgetsBindingObserver {
               : const HomeWidget(),
           debugShowCheckedModeBanner: false,
           builder: EasyLoading.init(),
-          supportedLocales: AppLocalizations.supportedLocales,
+          supportedLocales: appSupportedLocales,
+          localeResolutionCallback: localResolutionCallBack,
           localizationsDelegates: const [
             ...AppLocalizations.localizationsDelegates,
             S.delegate
@@ -87,7 +89,8 @@ class _EnteAppState extends State<EnteApp> with WidgetsBindingObserver {
           home: const HomeWidget(),
           debugShowCheckedModeBanner: false,
           builder: EasyLoading.init(),
-          supportedLocales: AppLocalizations.supportedLocales,
+          supportedLocales: appSupportedLocales,
+          localeResolutionCallback: localResolutionCallBack,
           localizationsDelegates: const [
             ...AppLocalizations.localizationsDelegates,
             S.delegate

lib/l10n/l10n.dart

@@ -4,3 +4,20 @@ import "package:photos/generated/l10n.dart";
 extension AppLocalizationsX on BuildContext {
   S get l10n => S.of(this);
 }
+
+// list of locales which are enabled for auth app.
+// Add more language to the list only when at least 90% of the strings are
+// translated in the corresponding language.
+const List<Locale> appSupportedLocales = <Locale>[
+  Locale('en'),
+];
+
+Locale localResolutionCallBack(locales, supportedLocales) {
+  for (Locale locale in locales) {
+    if (appSupportedLocales.contains(locale)) {
+      return locale;
+    }
+  }
+  // if device language is not supported by the app, use en as default
+  return const Locale('en');
+}

lib/ui/tools/app_lock.dart

@@ -3,6 +3,7 @@ import 'dart:async';
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 import "package:photos/generated/l10n.dart";
+import "package:photos/l10n/l10n.dart";
 
 /// A widget which handles app lifecycle events for showing and hiding a lock screen.
 /// This should wrap around a `MyApp` widget (or equivalent).
@@ -109,7 +110,8 @@ class _AppLockState extends State<AppLock> with WidgetsBindingObserver {
       themeMode: widget.savedThemeMode,
       theme: widget.lightTheme,
       darkTheme: widget.darkTheme,
-      supportedLocales: AppLocalizations.supportedLocales,
+      supportedLocales: appSupportedLocales,
+      localeResolutionCallback: localResolutionCallBack,
       localizationsDelegates: const [
         ...AppLocalizations.localizationsDelegates,
         S.delegate