Fix copy-pasted error message in unit test.

Signed-off-by: Krisztian Litkey <krisztian.litkey@intel.com>

Reject oversized messages on the sender side, keeping the
receiver side rejection intact. This should provide minimal
low-level plumbing for clients to attempt application level
corrective actions on the requestor side, if the high-level
protocol is designed with this in mind.

Co-authored-by: Alessio Cantillo <cantillo.trd@gmail.com>
Co-authored-by: Qian Zhang <cosmoer@qq.com>
Signed-off-by: Krisztian Litkey <krisztian.litkey@intel.com>

Co-authored-by: Alessio Cantillo <cantillo.trd@gmail.com>
Co-authored-by: Qian Zhang <cosmoer@qq.com>
Signed-off-by: Krisztian Litkey <krisztian.litkey@intel.com>

Use a dedicated, grpc Status-compatible error to wrap the
unique grpc status code, the size of the rejected message
and the maximum allowed size when a message is rejected
due to size limitations by the sending side.

Signed-off-by: Krisztian Litkey <krisztian.litkey@intel.com>

channel: reject oversized messages on the sender side(, too).