title: Unable to speak out the adaptive card content in cortana channel
body: <p>I've integrated my bot with cortana channel and can view the adaptive cards successfully.  What I need is to speak out the content of the adaptive card.  The speak property when using shows that it is deprecated.  Is there a way to speak out the content of my card? </p>
  
  <pre><code>var contentCard = AdaptiveCard(qnaAnswer.title);
   Attachment attachment = new Attachment()
     {
       ContentType = AdaptiveCard.ContentType,
       Content = contentCard
     }; 
        reply.Attachments = new List&lt;Attachment&gt; { attachment };
        await turnContext.SendActivityAsync(reply);
  
  public static AdaptiveCard AdaptiveCard(string subtitle)
   {
     AdaptiveCard card = new AdaptiveCard();           
     card.Body.Add(new AdaptiveTextBlock()
    {
     Text = string.IsNullOrEmpty(subtitle) ? string.Empty : subtitle,                         
     Speak =text ,
    });
  return card;
   }
  </code></pre>