Fixed ValidateAllProperties generation for generated properties

[Sergio0694]

Fixes #4184

PR Type

What kind of change does this PR introduce?

• Bugfix

What is the current behavior?

"If you annotate a field with ObservableProperty along with validation attributes, the generated source code for the ValidateAllProperties method doesn't include all the properties."

What is the new behavior?

The generated code for ValidateAllProperties is now correct.

PR Checklist

Please check if your PR fulfills the following requirements:

• Tested code with current supported SDKs
• New component
  • Pull Request has been submitted to the documentation repository instructions. Link:
  • Added description of major feature to project description for NuGet package (4000 total character limit, so don't push entire description over that)
  • If control, added to Visual Studio Design project
• Sample in sample app has been added / updated (for bug fixes / features)
  • Icon has been created (if new sample) following the Thumbnail Style Guide and templates
• New major technical changes in the toolkit have or will be added to the Wiki e.g. build changes, source generators, testing infrastructure, sample creation changes, etc...
• Tests for the changes have been added (for bug fixes / features) (if applicable)
• Header has been added to all new source files (run build/UpdateHeaders.bat)
• Contains NO breaking changes

[ghost]

Thanks Sergio0694 for opening a Pull Request! The reviewers will test the PR and highlight if there is any conflict or changes required. If the PR is approved we will proceed to merge the pull request 🙌

[michael-hawker]

@Sergio0694 looks like there's a conflict with your other PR now, want to resolve?

[Sergio0694]

@michael-hawker Done 😄

[ghost]

Hello @michael-hawker!

Because this pull request has the auto merge :zap: label, I will be glad to assist with helping to merge this pull request once all check-in policies pass.

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[michael-hawker]

@Sergio0694 want to resolve conflicts?

[Sergio0694]

@michael-hawker Done! 🚀

[michael-hawker]

@nickrandolph want to try out the preview package and let us know if this works for your scenario?