impl(GCS+gRPC): `MeterProvider` for gRPC metrics

[coryan]

Part of the work for #13998

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This change is 

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 99.28058% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 93.25%. Comparing base (1fd7015) to head (41dba71). Report is 7 commits behind head on main.

Files	Patch %	Lines
...orage/internal/grpc/metrics_meter_provider_test.cc	99.05%	1 Missing :warning:

Additional details and impacted files

@@           Coverage Diff            @@
##             main   #14229    +/-   ##
========================================
  Coverage   93.25%   93.25%            
========================================
  Files        2210     2212     +2     
  Lines      192825   192964   +139     
========================================
+ Hits       179816   179950   +134     
- Misses      13009    13014     +5     

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