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

@@            Coverage Diff            @@
##             master     #147   +/-   ##
=========================================
  Coverage     65.85%   65.85%           
  Complexity      108      108           
=========================================
  Files            18       18           
  Lines           779      779           
  Branches         11       11           
=========================================
  Hits            513      513           
  Misses          256      256           
  Partials         10       10           

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