UML writeAllowed stereotype for ServiceInterfacePoint:LayerProtocolName

[italobusi]

The writeAllowed stereotype for this attribute is CREATE_AND_UPDATE

However, as indicated in open issue #260 , since SIPs are shared knowledge, I think the stereotype should be WRITE_NOT_ALLOWED

It is worth noting that the YANG model is correct:

| +--ro layer-protocol-name* layer-protocol-name

It is not clear how the YANG tool has properly marked this list as read-only even if the UML writeAllowed stereotype was CREATE_AND_UPDATE