race condition inside opencensus ochttp when used inside google storage API

[Slach]

Please answer these questions before submitting a bug report.

What version of OpenCensus are you using?

0.23.0

What version of Go are you using?

1.17

What did you do?

googleapis/google-cloud-go#5664

What did you expect to see?

no race condition

What did you see instead?

race condition inside opencensus
storage.NewReader() fire different http requests and should provide different Span intance

Look to
https://github.com/googleapis/google-cloud-go/blob/main/storage/reader.go#L80-L96
and
https://github.com/googleapis/google-cloud-go/blob/main/internal/trace/trace.go#L28-L41