amazon-import doesn't allow specifying default EBS delete-storage-on-termination

#### Description

Wasn't sure if this was a bug report but seems more like a feature request.

I didn't see any indication in the exposed options for documentation for the equivalent option for `delete_on_termination` (https://www.packer.io/plugins/builders/amazon/ebs) for **Images** (not **Instances**).

I checked in

https://www.packer.io/plugins/post-processors/amazon

and in the source

https://github.com/hashicorp/packer-plugin-amazon/blob/v1.1.1/post-processor/import/post-processor.go#L420

but so no indication that this exists.

#### Use Case(s)

Without this you are forced to spin up the image again and perform some migration steps.

#### Potential configuration

{
"type": "amazon-import",
"delete_on_termination": true,
...
}

#### Potential References