[winmd servicebus] brokermessage*.text to be changed to brokermessage*.body

[deepakverma]

winmd code in dev branch: https://github.com/aliakb/azure-sdk-for-net/blob/17b26ab72d31af987b557c40127f83842e726305/microsoft-azure-servicelayer/Microsoft.WindowsAzure.ServiceLayer/ServiceBus/BrokeredMessageInfo.cs

Minor change - to be consistent with the .net api Text property should be renamed to "body".

[toddysm]

This is changed