[Platform][K8s] Backups are not deleted after deleting universe if "Delete Backups" checkbox is enabled.

[RP1807]

Description
In the k8s portal, when the user deletes the universe with the "Delete Backup" checkbox enabled, backups associated with that universe are not deleted. This is observed only with the k8s universe

Version: 2.6.0.0-b46

Steps to reproduce

1. Create a k8s universe in the portal.
2. Create S3 backups
3. Try to delete universe make sure you check "Delete Backups" in the delete universe pop-up
4. After universe deletion, go to the S3 bucket and observe that backup is not deleted.