[jaeger-v2] Dangerous use of tracer in plugin/storage/grpc/factory.go

[yurishkuro]

The factory is passed a tracer that it then passes to OTEL's ToClientConn() function, which automatically adds tracing instrumentation to gRPC connection. That means we may start generating new traces as we're trying to save spans to storage, thus causing an infinite loop of trace generation. The write path must always be devoid of tracing (or use very low sampling rate) to avoid this.