Add Java variants of WriteTo{Csv,Json}.

[robertwb]

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[robertwb]

R: @Abacn

[github-actions]

Stopping reviewer notifications for this pull request: review requested by someone other than the bot, ceding control

[codecov]

Codecov Report

Merging #28380 (5037d7c) into master (76fbb8e) will decrease coverage by 0.06%.
Report is 8 commits behind head on master.
The diff coverage is 1.63%.

@@            Coverage Diff             @@
##           master   #28380      +/-   ##
==========================================
- Coverage   72.23%   72.17%   -0.06%     
==========================================
  Files         685      686       +1     
  Lines      101519   101551      +32     
==========================================
- Hits        73328    73296      -32     
- Misses      26614    26676      +62     
- Partials     1577     1579       +2     

Flag	Coverage Δ
python	82.62% <1.63%> (-0.10%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
...s/python/apache_beam/testing/analyzers/__init__.py	100.00% <100.00%> (ø)
...ache_beam/testing/analyzers/github_issues_utils.py	0.00% <0.00%> (-40.91%)	⬇️
...hon/apache_beam/testing/analyzers/perf_analysis.py	16.21% <0.00%> (-0.69%)	⬇️
...ache_beam/testing/analyzers/perf_analysis_utils.py	13.84% <0.00%> (-4.61%)	⬇️

... and 7 files with indirect coverage changes

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[robertwb]

R: @johnjcasey

I think the Jenkins failures are infra issues.