title: How to implement confirm prompt default locale in node bot v4
body: <p>I am trying to do confirm prompt the user based on the user's prefered locale. but V4 bot prompting user in English as well eventhough Locale is spanish.</p>
  
  <p>Here is my code in v4 node:</p>
  
  <pre><code> const { ConfirmPrompt } = require('botbuilder-dialogs');
      const CONFIRM_PROMPT_ES = 'confirmPrompt_ES';
      const CONFIRM_PROMPT_EN = 'confirmPrompt_EN';
  
  // added dialogs to dialogSet
  
      this.addDialog(new ConfirmPrompt(CONFIRM_PROMPT_ES,false,**'es-mx'**))
                  .addDialog(new ConfirmPrompt(CONFIRM_PROMPT_EN))
  
  
  
             if(constant.lang==='es'){
             console.log('---entered into spanish prompt block---');
               stepContext.context.activity.locale='es-mx';
             return await stepContext.prompt(CONFIRM_PROMPT_ES, { prompt: constant.liketostorevin }); 
         }
         else{
             console.log('---entered into english prompt block---');
              return await stepContext.prompt(CONFIRM_PROMPT_EN, { prompt: constant.liketostorevin });
         }
  </code></pre>
  
  <p>Please let me know if anyone know the way how to handle. thanks in advance.</p>