feat: Support Amplify Android Lazy Types and Custom Selection Set

[tylerjroach]

Description of changes

Amplify Android will now support lazy loading and custom selection set with the existing cli.json generatemodelsforlazyloadandcustomselectionset flag already in use by iOS.

Issue #, if available

Amplify Android Work: https://github.com/aws-amplify/amplify-android/tree/tjroach/custom-selection-set
Documentation: TBD

Description of how you validated changes

The newly generated models have been tested in an Amplify Android feature branch.

Checklist

• PR description included
• yarn test passes
• Tests are changed or added
• Relevant documentation is changed or added (and PR referenced)
• Breaking changes to existing customers are released behind a feature flag or major version update
• Changes are tested using sample applications for all relevant platforms (iOS/android/flutter/Javascript) that use the feature added/modified

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

[tylerjroach]

Closing until an addition to check if DataStore is enabled. Since lazy and custom select set support is only being added to the Api category on Android now, if data store is being used (even if the generatemodelsforlazyloadandcustomselectionset cli flag is enabled), the models should not generate with lazy support.

[tylerjroach]

Closing until the above comment is resolved.

[dpilch]

I started E2E tests for this change: https://us-east-1.console.aws.amazon.com/codesuite/codebuild/594813022831/projects/amplify-codegen-e2e-workflow/batch/amplify-codegen-e2e-workflow:c2e5ffd2-93b3-4422-99b1-eb68b5b43f8f?region=us-east-1