Elasticsearch domain should enable encryption

Description

Implement encryption at rest for your Amazon Elasticsearch (ES) domain with the AWS KMS service.

Implementing encryption at rest protects your domain from unauthorized access and ensures security and compliance requirements are met.

Follow the Enabling Encryption of Data at Rest docs to learn how to implement encryption for your domain.

Run describe-elasticsearch-domain with your ES domain to return configuration metadata.
```
aws es describe-elasticsearch-domain
    --domain-name your-es-domain
```
Run create-elasticsearch-domain with your domain name and encryption-at-rest-options. Use the metadata returned in the previous step to create and relaunch your ES domain to enable at-rest encryption.
```
aws es create-elasticsearch-domain
    --domain-name your-es-domain
    ...
    --encryption-at-rest-options Enabled=true,KmsKeyId="abcdabcd-aaaa-bbbb-cccc-abcdabcdabcd"
```