Add flag to control automatic exception sampling in Python (disabled)

[rohdesamuel]

This enables exception sampling when either the "enable_data_sampling" or "enable_always_on_exception_sampling" experiment is present. This disables automatic exception sampling when "disable_always_on_exception_sampling" is given.

---

Thank you for your contribution! Follow this checklist to help us incorporate your contribution quickly and easily:

• Mention the appropriate issue in your description (for example: addresses #123), if applicable. This will automatically add a link to the pull request in the issue. If you would like the issue to automatically close on merging the pull request, comment fixes #<ISSUE NUMBER> instead.
• Update CHANGES.md with noteworthy changes.
• If this contribution is large, please file an Apache Individual Contributor License Agreement.

See the Contributor Guide for more tips on how to make review process smoother.

To check the build health, please visit https://github.com/apache/beam/blob/master/.test-infra/BUILD_STATUS.md

GitHub Actions Tests Status (on master branch)

See CI.md for more information about GitHub Actions CI or the workflows README to see a list of phrases to trigger workflows.

[rohdesamuel]

R: @udim

[github-actions]

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

[codecov]

Codecov Report

Merging #28418 (cd8bfec) into master (1225dee) will decrease coverage by 0.02%.
Report is 26 commits behind head on master.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master   #28418      +/-   ##
==========================================
- Coverage   72.33%   72.31%   -0.02%     
==========================================
  Files         682      683       +1     
  Lines      100541   100633      +92     
==========================================
+ Hits        72723    72771      +48     
- Misses      26243    26287      +44     
  Partials     1575     1575              

Flag	Coverage Δ
python	82.82% <100.00%> (-0.05%)	⬇️

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

Files Changed	Coverage Δ
.../python/apache_beam/runners/worker/data_sampler.py	98.19% <100.00%> (+0.16%)	⬆️
...ks/python/apache_beam/runners/worker/operations.py	75.21% <100.00%> (+0.03%)	⬆️
...thon/apache_beam/runners/worker/sdk_worker_main.py	78.03% <100.00%> (+0.32%)	⬆️

... and 9 files with indirect coverage changes

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[udim]

If both of these flags are true, only exception sampling is enabled

[rohdesamuel]

Ah gotcha, looks like Java has the logic but not here. Added it here and added a test.

[udim]

The Java PR has the additional check: https://github.com/apache/beam/pull/28403/files#diff-36700390d81df614d72f1040b223c74ce99a4615ab209bbbe7ee4675f8c16ae3R75

[rohdesamuel]

Run Python_Runners PreCommit

[rohdesamuel]

Run Portable_Python PreCommit