chore: use v1 transformer supported region for schema searchable test

[AaronZyLee]

Description of changes

The schema-searchable is using the v1 transformer which generates t2.small.elasticsearch instance type. The type is not available in all regions. The split e2e script is updated to assign the regions supported for v1 transformer only to this test.

CDK / CloudFormation Parameters Changed

Issue #, if available

Description of how you validated changes

The cloud e2e test is passing.

Checklist

• PR description included
• yarn test passes
• Tests are changed or added
• Relevant documentation is changed or added (and PR referenced)
• New AWS SDK calls or CloudFormation actions have been added to relevant test and service IAM policies
• Any CDK or CloudFormation parameter changes are called out explicitly

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