fix(amf): Wrong enum causes for Radio Network Layer causes for N11 protocol

[brunohcfaria]

Your Environment

• Version: 1.8
• Affected Component: Access Gateway
• Affected Subcomponent: oai_mme
• Deployment Environment: bare-metal (AGW), Vagrant (AGW)

Describe the Issue

The causes enumerator related to N11 Radio Network Layer is wrong resulting in unexpected protocol handling.

To Reproduce

gNB initiated Error Indication Messager with cause: RadioNetworkLayer:UNKNOWN_LOCAL_UE_NGAP_ID leads to AMF keep trying to release and existent UE context in the gNB.

Expected behavior

The gNB shall silently release the local UE context indicated in the Error Indicaion Message with cause RadioNetworkLayer:UNKNOWN_LOCAL_UE_NGAP_ID.

[jao-tm]

I still get this error, even with the fix: