[BUG] Can't launching non EBS builders with a specific dedicated host

[arantesxyz]

Description

When building a non EBS instance with the following code it fails with InsufficientHostCapacity

placement {
  tenancy = "host"
  host_id = var.host_id
}

The cloudtrail logs shows the id was never sent to AWS. And looking at the code looks like it was missing , this PR fixes it.

Rollback Plan

If a change needs to be reverted, we will roll out an update to the code within 7 days.
Just reverting the PR should be fine.

Changes to Security Controls

Are there any changes to security controls (access controls, encryption, logging) in this pull request? If so, explain.
No.

[hashicorp-cla-app]

All committers have signed the CLA.