Replace embedded template conditionals

[kaamfor]

Hi everyone, thank you for your work! I started using Ansible a couple of months ago, and this repo was an excellent starting point for automating VM creation. However, I have faced some issues related to recent Ansible guideline:

• source: https://docs.ansible.com/ansible/latest/porting_guides/porting_guide_9.html#playbook
• more discussion at 2.16 unsafe conditionals check - Just makes things harder? ansible/ansible#82833

So I tried to address this and made some fixes in assert_vars.yml and a small change in one of Terraform templates.