CloudFormation OpenSearch upgrade issue

This reproduces an odd issue with CloudFormation upgrading OpenSearch engine versions.

1. Deploy the 00-initial.yml template as a new stack.
2. Try to update the stack with the 02-final.yml template. This fails as you cannot directly upgrade an OpenSearch domain from Elasticsearch 7.10 to OpenSearch 2.19.
3. Upgrade the domain manually using the OpenSearch console - first to OpenSearch 1.3 and then to OpenSearch 2.19.
4. Try again to update the stack with the 02-final.yml template. This fails with an Internal Failure. In CloudTrail we can see an UpgradeDomain event at this time with an errorMessage Failed to submit upgrade. Upgrade from OpenSearch_2.19 to OpenSearch_2.19 not supported.
   • The stack is now in UPDATE_ROLLBACK_FAILED, because the rollback tried to downgrade the cluster back to Elasticsearch 7.10. Continue the rollback, skipping the OpenSearch domain, to get the stack back to a usable state.
5. Update the stack with the 01-intermediate.yml template. This should succeed.
6. Update the stack with the 02-final.yml template. This should also now succeed.