Update checkstyle (v8.19)

[epeee]

see release notes for details

[codecov[bot]]

Codecov Report

Merging #819 into master will not change coverage. The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #819   +/-   ##
=========================================
  Coverage     94.25%   94.25%           
  Complexity      475      475           
=========================================
  Files           156      156           
  Lines          2244     2244           
  Branches         77       77           
=========================================
  Hits           2115     2115           
  Misses           61       61           
  Partials         68       68

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[mockitoguy]

+1