fix: Fix availability dip in PropagateTags property

[GavinZZ]

Issue #, if available

Description of changes

Dip fix on PropagateTags property.

Description of how you validated changes

All tests passed.

Checklist

• Adheres to the development guidelines
• Add/update transform tests
  • Using correct values
  • Using wrong values
• Add/update integration tests

Examples?

Please reach out in the comments if you want to add an example. Examples will be
added to sam init through aws/aws-sam-cli-app-templates.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[ssenchenko]

Maybe add a test?

[GavinZZ]

The reason I did not add a test is because We do validation on template which caused

    def on_before_transform_template(self, template_dict):  # type: ignore[no-untyped-def]
        """
        Hook method that runs before a template gets transformed. In this method, we parse and process Globals section
        from the template (if present).
    
        :param dict template_dict: SAM template as a dictionary
        """
        try:
            global_section = Globals(template_dict)
        except InvalidGlobalsSectionException as ex:
>           raise InvalidDocumentException([ex]) from ex
E           samtranslator.model.exceptions.InvalidDocumentException: [InvalidGlobalsSectionException('Globals', 'Value of ${section} must be a dictionary')]

I think it's a trivial enough task and it is not worth the trouble to figure out how to bypass it and add this test.