grpc: revert #8278: Fix cardinality violations in non-server streaming RPCs

[arjan-bal]

Related issue: #7286

This reverts commit a64d933.

This change is breaking an internal test cl/774621745. A rollback is being performed to fix the broken test while we investigate the failure.

RELEASE NOTES: N/A

[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 82.39%. Comparing base (bdbe6a2) to head (2db9aa5).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
stream.go	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #8404      +/-   ##
==========================================
- Coverage   82.43%   82.39%   -0.04%     
==========================================
  Files         413      413              
  Lines       40430    40424       -6     
==========================================
- Hits        33328    33309      -19     
- Misses       5751     5754       +3     
- Partials     1351     1361      +10     

Files with missing lines	Coverage Δ
stream.go	81.65% <50.00%> (+0.15%)	⬆️

... and 18 files with indirect coverage changes

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