Adjust to current Semantic Conventions (https://opentelemetry.io/docs/specs/semconv/rpc/)

[kago-dk]

Adjust the keys to the current Semantic Conventions (https://opentelemetry.io/docs/specs/semconv/rpc/), so that OpenTelemetry Weaver does not fail on them.
https://github.com/dotnet/orleans/blob/main/src/Orleans.Core.Abstractions/Diagnostics/ActivityTagKeys.cs