Get a list of locale file names in the given locale dir.

def get_locale_choices(locale_dir):
        """
        Get a list of locale file names in the given locale dir.
        """
        #/
        file_name_s = os.listdir(locale_dir)
        
        #/
        choice_s = []
        
        for file_name in file_name_s:
            if file_name.endswith(I18n.TT_FILE_EXT_STXT):
                file_name_noext, _ = os.path.splitext(file_name)
                if file_name_noext:
                    choice_s.append(file_name_noext)
        
        #/
        choice_s = sorted(choice_s)
         
        #/
        return choice_s