title: Upload object to s3 using aws api gateway service proxy
body: <p>can any one help 
  i have configured aws api gateway with post method using aws service proxy integration type, then i have configured the resource as s3 and gave bucket details as sub domain
  in action type i specefied PutObject finally created arn and used that,after all doing this i am able create a random folder in bucket but unable to upload a file which is json type</p>