OCProtoToJaegerProto appends parent to the end of references, parent should be first

[william-tran]

This block runs after the references list is put together: https://github.com/open-telemetry/opentelemetry-collector/blob/v0.3.0/translator/trace/jaeger/protospan_to_jaegerproto.go#L490-L501

Jaeger UI assumes the parent is the first reference and has no parent span ID in its object model, so it renders the trace incorrectly. This was encountered when trying to resolve jaegertracing/jaeger-client-java#705. My setup is jaeger thrift http -> otel-collector -> jaeger grpc -> jaeger.

[tigrannajaryan]

@dmitryax is this related to what you found recently?

[dmitryax]

@tigrannajaryan yes, this is related, but a bit different issue.

It makes sense to put parent as the first reference in the list. I'll apply it in the the new jaeger exporter.

[william-tran]

Thanks for taking this on, I have another more general issue open-telemetry/opentelemetry-specification#562 that might be of interest as this translation work continues.