Ensure database retention is enabled for Amazon Relational Database Service (Amazon RDS) cluster

AWS RDS database instances does not have backup retention enabled. This may impact the availability of data and affect disaster recovery plan.

In AWS Console -

1. Sign in to the AWS Console and open the RDS Console.
2. Under Databases, choose the cluster you wish to edit.
3. Select Modify.
4. Expand the Additional configuration section.
5. Under Backup, set the Backup retention period to something greater than 7 days.

In Terraform -

1. In the aws_rds_cluster resource, set the value for backup_retention_period to something greater than 7 days.

References:
https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_CommonTasks.BackupRestore.html
https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/rds_cluster#backup_retention_period