title: Flutter: Application's locale is not supported by all of its localization delegates
body: <p>Hello I am trying add BottomNavigationBar in flutter app but when i run project error occures :</p>
  
  <pre><code>A MaterialLocalizations delegate that supports the ka_GE locale was not found
  </code></pre>
  
  <p>This is my app delegates:</p>
  
  <pre><code>  supportedLocales: [
      const Locale('en', 'US'),
      const Locale('ka', 'GE'),
      const Locale('ru', 'RU'),
    ],
    localizationsDelegates: [
      const InfosLocalizationsDelegate(),
      GlobalMaterialLocalizations.delegate,
      GlobalWidgetsLocalizations.delegate
    ],
    locale: Locale('ka')
  </code></pre>
  
  <p>This is Custom LocalizationsDelegate:</p>
  
  <pre><code>class CLocalizationsDelegate
      extends LocalizationsDelegate&lt;CLocalizations&gt; {
    const CLocalizationsDelegate();
  
    @override
    bool isSupported(Locale locale) =&gt;
        ['en', 'ka', 'ru'].contains(locale.languageCode);
  
    @override
    Future&lt;CLocalizations&gt; load(Locale locale) async {
      CLocalizations localizations = new CLocalizations(locale);
      await localizations.load();
      print("Load ${locale.languageCode}");
      return localizations;
    }
  
    @override
    bool shouldReload(CLocalizationsDelegate old) =&gt; false;
  }
  </code></pre>
  
  <p>Yeah I know that the problem is 'ka' because MaterialLocalizations doesn't not supports it  but I have to solve that problem, so guys can you help me out?</p>