fix(otel): async read write stream tracing

[dbolduc]

Part of the work for #14371

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Running the streaming_pull_subscriber cpp sample:

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This change is 

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.09%. Comparing base (d9ffe82) to head (8687c2b).
Report is 5 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #14379   +/-   ##
=======================================
  Coverage   93.09%   93.09%           
=======================================
  Files        2191     2191           
  Lines      193032   193037    +5     
=======================================
+ Hits       179705   179716   +11     
+ Misses      13327    13321    -6     

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