Add customization in S3 to keep expires as timestamp type

[zoewangg]

Motivation and Context

Add customization in S3 to keep expires as timestamp type

Modifications

• Update ShapeSubstitutionsProcessor to handle emitAsType
• Add customization in S3 to keep expires as timestamp type

Testing

• Added unit tests
• Changed expires to string type in s3 and verified with japicmp that no breaking changes are introduced.

Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Checklist

• I have read the CONTRIBUTING document
• Local run of mvn install succeeds
• My code follows the code style of this project
• My change requires a change to the Javadoc documentation
• I have updated the Javadoc documentation accordingly
• I have added tests to cover my changes
• All new and existing tests passed
• I have added a changelog entry. Adding a new entry must be accomplished by running the scripts/new-change script and following the instructions. Commit the new file created by the script in .changes/next-release with your changes.
• My change is to implement 1.11 parity feature and I have updated LaunchChangelog

License

• I confirm that this pull request can be released under the Apache 2 license

[sonarqubecloud]

Quality Gate failed

Failed conditions
C Reliability Rating on New Code (required ≥ A)

See analysis details on SonarCloud

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[L-Applin]

Just for my understanding, what is this SdkCustomization_ name prefix for?

[zoewangg]

This is for the case where we need to add a new type to the service model. In this case, we are adding "SdkCustomization_ expires": {"type": "timestamp"} to S3 since it doesn't have a generic timestamp type.