Fix zap grpclogger verbosity check

[bouk]

Currently it only logs entries that are lower or equal to the
configured level, when you want the opposite. This means that by default
only INFO messages are logged, and anything more urgent is dropped.

[johanbrandhorst]

Hi, thanks for this PR! Could you add a test to check that this is indeed the correct behavior? Thanks!

[bouk]

Added!

[codecov-io]

Codecov Report

Merging #366 (78812ab) into master (c05cb40) will increase coverage by 0.60%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #366      +/-   ##
==========================================
+ Coverage   72.81%   73.42%   +0.60%     
==========================================
  Files          41       41              
  Lines        1317     1317              
==========================================
+ Hits          959      967       +8     
+ Misses        304      296       -8     
  Partials       54       54              

Impacted Files	Coverage Δ
logging/zap/grpclogger.go	30.76% <100.00%> (+30.76%)	⬆️

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[johanbrandhorst]

Thanks for your contribution! Could you please cherry pick this against the v2 branch?

[bouk]

The v2 branch doesn't seem to do anything with the global grpc logger

[fxrlv]

verbosity IS NOT about logging level
grpclog package logs error by calling method (*zapGrpcLoggerV2).Error*
verbosity controls how much details we log, NOT level
could you please revert this pull request?