modifle instnace.yml

vars:
  instance_id: i-1234564542134
  cpu_credit_specification: unlimited
  security_group: 
    - default
    - someother

tasks:
  - name: try to modify the ec2 instance
      ec2_instance:
        instance_ids: "{{ instance_id }}"
        cpu_credit_specification: "{{ cpu_credit_specification }}"
        security_groups: "{{ security_group }}"
        purge_tags: no