Changed GeneratedServiceMetadataProvider to lazily load elements. Updated unit tests based to reflect changes.

[awmcc90]

Motivation and Context

GeneratedServiceMetadataProvider takes a while to initialize. This was benchmarked and shown in this ticket. Lazily loading metadata significantly reduces the overhead required to initialize this class and reduces the time it takes to load substantially. This is important in the era of serverless infrastructure where cold start times need to be minimized.

Resolves #3664

Modifications

• All changes scoped to the codegen-lite package
• Changed ServiceMetadataProviderGenerator
  • Removed initialization of all ServiceMetadata entries in the constructor
  • Added codegen method to create a static ServiceMetadata factory method which accepts a String value (same as before) and generates the associated ServiceMetadata when required.
  • Updated codegen methods to add logic required for calling new factory method
  • Created ServiceMetadata objects are cached using the same map as before and this is checked prior to calling the factory
• Updated test resource service-metadata-provider.java to reflect new GeneratedServiceMetadataProvider structure

Testing

• Updated unit tests and confirmed they succeeded
• Testing environment:
  • amazon corretto 11 jdk
  • MacOS Monterey 12.6.2

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