message: Add videoStreamingCapability in SystemCapability struct
  Reflecting review comments.
diff: </param>
  <param name="phoneCapability" type="PhoneCapability" mandatory="false">
  </param>
  + <param name="videoStreamingCapability" type="VideoStreamingCapability" mandatory="false">
  + </param>
  </struct>
  <!-- Requests/Responses -->
  