Creates a security policy to be used by one or more OpenSearch Serverless collections. Security policies provide access to a collection and its OpenSearch Dashboards endpoint from public networks or specific VPC endpoints. They also allow you to secure a collection with a KMS encryption key. For more information, see <a href="https://docs.aws.amazon.com/opensearch-service/latest/developerguide/serverless-network.html">Network access for Amazon OpenSearch Serverless</a> and <a href="https://docs.aws.amazon.com/opensearch-service/latest/developerguide/serverless-encryption.html">Encryption at rest for Amazon OpenSearch Serverless</a>.