fix: normalize the open api version

[xazhao]

Issue #, if available

In Serverless Api, if OpenApiVersion is different from openapi value in DefinitionBody, SAM will missconfigure the updated openApi definition body.

Description of changes

When openapi is in the DefinitionBody, we use that value instead of OpenApiVersion property in the resource.

Description of how you validated changes

Transform tests covering both cases.

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.

[GavinZZ]

I don't see how we handle the scenario when open api version mismatches between definition body and api property.

[xazhao]

I don't see how we handle the scenario when open api version mismatches between definition body and api property.

Basically when openapi exists in definition body, we use that value and ignore OpenApiVersion property with the following code:

normalized_open_api_version = definition_body.get("openapi", self.open_api_version)