[BUG] Azure Functions - Service Name can't be the Artifact Name

[rfavreau]

APM Agent version

The version of the Elastic.Apm nuget package used is 1.26

Environment

Operating system and version:
Azure Functions
.NET Framework/Core name and version (e.g. .NET 4.6.2, NET Core 3.1.100) :
.Net Core 8
Application Target Framework(s) (e.g. net462, netcoreapp3.1):
dotnet-isolated

Describe the bug

It's not possible to set the service name with the discover default service name (Artifact name). It's always overwrite by the Azure Functions name.

To Reproduce

Steps to reproduce the behavior:

1. Deploy an Azure Function with the APM Agent like described in the documentation
2. Then call your function trigger (for exemple an HttpTrigger)
3. Then check the Service Name into the APM page
4. This Service Name will be the Azure Functions name and not the Artifact name

Expected behavior

With the ELASTIC_APM_SERVICE_NAME environment variable, we can update this Service Name but never with the Artifact Name. To have the same namming convention that the .Net Applications (into the APM page), i expecte to have the Artifact Name.