Handle termination_protection parameter when restarting instances (#5076)
Handle termination_protection parameter when restarting instances (#5076)

* Restart EC2 instances with multiple network interfaces

A previous bug, #3234, caused instances with multiple ENI's to fail when being
started or stopped because sourceDestCheck is a per-interface attribute, but we
use the boto global access to it (which only works when there's a single ENI).

This patch handles a variant of that bug that only surfaced when restarting an
instance, and catches the same type of exception.

* Default termination_protection to None instead of False

AWS defaults the value of termination_protection to False, so we don't
need to explicitly send `False` when the user hasn't specified a
termination protection level. Before this patch, the below pair of tasks
would:

1. Create an instance (enabling termination_protection)
2. Restart that instance (disabling termination_protection)

Now, the default None value would prevent the restart task from
disabling termination_protection.

```
- name: make an EC2 instance
  ec2:
    vpc_subnet_id: {{ subnet  }}
    instance_type: t2.micro
    termination_protection: yes
    exact_count: 1
    count_tag:
       Name: TestInstance
    instance_tags:
       Name: TestInstance
    group_id: {{ group }}
    image: ami-7172b611
    wait: yes
- name: restart a protected EC2 instance
  ec2:
    vpc_subnet_id: {{ subnet  }}
    state: restarted
    instance_tags:
       Name: TestInstance
    group_id: {{ group }}
    image: ami-7172b611
    wait: yes
```

thaim/ansible,thaim/ansible