deps: update dependency com.google.protobuf:protobuf-java to v3.12.2

[renovate-bot]

This PR contains the following updates:

Package	Update	Change
com.google.protobuf:protobuf-java	patch	3.12.0 -> 3.12.2

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[codecov]

Codecov Report

Merging #177 into master will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #177   +/-   ##
=========================================
  Coverage     71.56%   71.56%           
  Complexity      132      132           
=========================================
  Files            12       12           
  Lines          1020     1020           
  Branches         18       18           
=========================================
  Hits            730      730           
  Misses          270      270           
  Partials         20       20           

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