Ensure IMDSv1 is disabled for AWS EC2 instances

AWS EC2 instances that have IMDSv1 enabled are vulnerable to server side request forgery (SSRF) attacks.

In AWS Console -

1. When launching a new instance in the Amazon EC2 console, select the following options on the Configure Instance Details page:
   a. Under Advanced Details, for Metadata accessible, select Enabled.
   b. For Metadata version, select V2.

In Terraform -

1. For the aws_instance resource, set the metadata_options.http_endpoint field to disabled.
2. Set the metadata_options.http_tokens field to required.

References:
https://docs.aws.amazon.com/AWSEC2/latest/WindowsGuide/configuring-instance-metadata-service.html
https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/instance#metadata_options