#### Description
Move SDK construction into service/telemetry. This is a step towards
fully encapsulating the otelconf SDK in the service/telemetry package,
so we can have different telemetry provider implementations that can be
injected.
#### Link to tracking issue
Preparation work for
https://github.com/open-telemetry/opentelemetry-collector/issues/4970
#### Testing
N/A, non-functional change.
#### Documentation
N/A
Andrew Wilkins