* Send error response when update metadata fails.
Keeping it simple for the first implementation.
- Send error response only if request_id != 0
- Two kinds of errors notified
o does not have permissions - NOT_ALLOWED
o attributes exceeds size limits - INVALID_ARGUMENT
* Check size limits on metadata and name set from client.
Added a name length limit also.
* check name length in service update participant path also
* limit check in limit config
* update protocol
* longer keys
Raja Subramanian