am 998234e: AI 147947: update the sitemap. add disallow in robots file f

Merge commit '998234ed4ab957b9ddb15f4ad5341885a6a649c2' into donut

* commit '998234ed4ab957b9ddb15f4ad5341885a6a649c2':
  AI 147947: update the sitemap. add disallow in robots file for the sdk/preview/