MediaHTTPConnection: support Cookie update

- The server side would keep the Cookie in the
  response header. The client should update it
  in the http connection session.

- disable the functionality as it's server specific.
  enable it by "adb shell setprop persist.media.cookie.cust
  true"

Change-Id: Ibde2dbb228856200ea1ecbfa391f8480b5595ae9