Adaptive card is not rendered on android phone

Hi 

We have an external bot configured to use MS Teams channel using message end point web hook. The following is the message posted to the  Ms Teams channel by the external bot. This response gets rendered as expected when MS Teams is accessed via web browser or MS Teams application on desktop computer. However,  the card is not rendered at all (seeing an empty line/block without any content)  when used with  Teams application on android mobile phone. What is going wrong here? Am I missing something?  

{ 
   "channelData":{ 
      "tenant":{ 
         "id":"xxxxxxxxxxxxxx"
      }
   },
   "attachments":[ 
      { 
         "contentType":"application/vnd.microsoft.card.adaptive",
         "content":{ 
            "fallbackText":"Adaptive card version not supported",
            "type":"AdaptiveCards",
            "body":[ 
               { 
                  "text":"Here is an adaptive card with a link to a task module",
                  "type":"TextBlock"
               },
               { 
                  "type":"Image",
                  "url":"http://adaptivecards.io/content/cats/1.png"
               }
            ],
            "version":"1.0",
            "actions":[ 
               { 
                  "type":"Action.OpenUrl",
                  "title":"Open Link",
                  "url":"https://teams.microsoft.com/l/task/xxxxx?url=https%3A%2F%2Fwww.wikipedia.com%0A&height=large&width=large&title=Wikipedia-Embed"
               }
            ]
         }
      }
   ],
   "replyToId":"xxxxxx",
   "serviceUrl":"https://smba.trafficmanager.net/amer/",
   "recipient":{ 
      "name":"xxxx xxxx",
      "aadObjectId":"xxxxx",
      "id":"xx:xxxxxxxx"
   },
   "localTimestamp":"2020-02-14T15:21:41.1360000-08:00",
   "channelType":"msteams",
   "from":{ 
      "name":"xxxxxx",
      "id":"xx:xxxxx"
   },
   "type":"message",
   "conversation":{ 
      "conversationType":"personal",
      "tenantId":"xxxxxx",
      "id":"x:xxxxxx"
   }
}