Serialize boolean type only for non-nullable values

[mshaaban088]

Issue: #3400

What I did

Serialized boolean type only for non-nullable values

How to test

Is this testable with Jest or Chromatic screenshots?
No

Does this need a new example in the kitchen sink apps?
No

Does this need an update to the documentation?
No

If your answer is yes to any of these, please make sure to include it in your PR.

For maintainers only: Please tag your pull request with at least one of the following:
["cleanup", "BREAKING CHANGE", "feature request", "bug", "documentation", "maintenance", "dependencies", "other"]

[codecov]

Codecov Report

Merging #3432 into master will not change coverage.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master    #3432   +/-   ##
=======================================
  Coverage   37.05%   37.05%           
=======================================
  Files         463      463           
  Lines       10219    10219           
  Branches      924      936   +12     
=======================================
  Hits         3787     3787           
+ Misses       5891     5862   -29     
- Partials      541      570   +29

Impacted Files	Coverage Δ
addons/knobs/src/components/types/Boolean.js	11.62% <100%> (ø)	⬆️
addons/storysource/src/loader/traverse-helpers.js	60.86% <0%> (ø)	⬆️
addons/storysource/src/loader/parsers/index.js	44.44% <0%> (ø)	⬆️
addons/viewport/src/manager/components/Panel.js	37.26% <0%> (ø)	⬆️
.../ui/components/stories_panel/stories_tree/index.js	40% <0%> (ø)	⬆️
addons/actions/src/lib/types/function/index.js	77.77% <0%> (ø)	⬆️
addons/info/src/components/types/PropertyLabel.js	78.94% <0%> (ø)	⬆️
addons/jest/src/hoc/provideJestResult.js	0% <0%> (ø)	⬆️
lib/ui/src/modules/api/index.js	0% <0%> (ø)	⬆️
addons/graphql/src/components/FullScreen/index.js	0% <0%> (ø)	⬆️
... and 58 more

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