Enabled ENA networking and SRIOV support

What does this MR do?

Closes #3582 (closed)

Before accepting the merge request we should:

1. Confirm that our base image ami-6edd3078 has drivers for both sriov support and ena support.
2. Build the AMI and confirm that both booleans have been activated.

Checklist

See Definition of done.

• Change added to CHANGELOG.md. Not applicable for Documentation changes and minor changes.
• Documentation created/updated
• Tests added
• Integration tests added to GitLab QA, if applicable
• MR targeting master branch
• MR has a green pipeline on GitLab.com

Reviewer Checklist

In addition to above, reviewer must:

• Pipeline is green on dev.gitlab.org if the change is not touching documentation or internal cookbooks

References

#3582 (closed)

https://github.com/hashicorp/packer/pull/4312#issuecomment-280367422

https://github.com/hashicorp/packer/issues/5093

https://github.com/hashicorp/packer/pull/5284