Conform client's tracing interceptor to OTel's conventions #60

Job	Run time
Unit tests / Construct unit test matrix	3s
Cxx interop / Construct Cxx interop matrix	3s
Soundness / Check generated code	1m 51s
Soundness / Swift license headers check	6s
Soundness / API breakage check	2m 5s
Soundness / Unacceptable language check	3s
Soundness / Documentation check	1m 32s
Soundness / Broken symlinks check	3s
Soundness / Format check	31s
Soundness / License headers check	3s
Soundness / Python lint check	7s
Soundness / Shell check	35s
Soundness / YAML lint check	3s
Unit tests / Unit tests / Linux (6.0)	1m 31s
Unit tests / Unit tests / Linux (nightly-6.1)	1m 48s
Unit tests / Unit tests / Linux (nightly-main)	1m 39s
Cxx interop / Cxx interop / Linux (6.0)	1m 31s
Cxx interop / Cxx interop / Linux (nightly-6.1)	1m 44s
Cxx interop / Cxx interop / Linux (nightly-main)	1m 40s
	16m 58s

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