ec2_vol_facts: Include volume encryption status

[rouge8]

ISSUE TYPE

• Feature Pull Request

COMPONENT NAME

ec2_vol_facts

ANSIBLE VERSION

ansible 2.1.2.0
  config file =
  configured module search path = Default w/o overrides

SUMMARY

Include whether or not a volume is encrypted in the results.

After:

        {
            "attachment_set": {
                "attach_time": "2016-04-18T02:41:35.000Z",
                "device": "/dev/sdi",
                "instance_id": "i-foo",
                "status": "attached"
            },
            "create_time": "2016-04-18T02:41:28.333Z",
            "encrypted": true,
            "id": "vol-foo",
            "iops": null,
            "region": "us-west-1",
            "size": 50,
            "snapshot_id": "",
            "status": "in-use",
            "tags": {},
            "type": "standard",
            "zone": "us-west-1b"
        }

[rouge8]

Migrated from ansible/ansible-modules-extras#3306

[ryansb]

Thanks for your contribution!

[resmo]

cherry picked to 2.2