NoReboot option in amazon-ebs builder

#### Description

Please add the option to set NoReboot on the CreateImage in the amazon-ebs builder.

#### Use Case(s)

AWS reboots the instance before creating the image to ensure data integrity. We use packer to build golden images which are fully preconfigured/preinstalled. In the build we only enable services but don't start them. The reboot during the AWS image build does trigger the starting of those services which then try to connect to cluster and start sending metrics/logs to our observability. We would like to use the `NoReboot` option from the API to prevent this but I don't see how I can do this from packer. We realise the risks of `NoReboot` but think we can mitigate them by forcing fs synchronisation in a provisioner script. (ps we are migrating from Openstack which does not have this behaviour)

#### Potential References

NoReboot: https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_CreateImage.html