Use counter value as payload body

[junglie85]

Current example throws an exception after the first two responses due to the value returned from incrementAndGet exceeding the enum value range for PayloadType. I've updated the example to set the payload type as COMPRESSABLE and the payload body as the int value from incrementAndGet. It also serves as a simple example of how to convert to and from a ByteString.

Hope it's useful.

[pmlopes]

Thanks!