Set Span Kinds in Otel tracer interceptors

[yuandrew]

Is your feature request related to a problem? Please describe.
A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
Python, .NET, and Ruby all set span kinds in their OTel tracer interceptors

Describe the solution you'd like
A clear and concise description of what you want to happen.
Go should also set their span kinds. client as the outbound span kind, and server as the inbound span kind

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.