##### SUMMARY
`docker_container` should so some sanity checks that not two volumes / mount points use the same target inside the container, so that especially when recreating containers, they won't be destroyed first before recreating fails.

This becomes more important once #49808 is merged.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
docker_container

##### ANSIBLE VERSION
```
2.8.0
```

- name: TestingNet2
    purge_networks: yes
- name: Remove container from all networks
  docker_container:
    name: sleepy
    purge_networks: yes
- name: Start a container and use an env file
  docker_container:
    name: agent
    image: jenkinsci/ssh-slave
    env_file: /var/tmp/jenkins/agent.env
- name: Create a container with limited capabilities
  docker_container:
    name: sleepy
    image: ubuntu:16.04
    command: sleep infinity
    capabilities:
      - sys_time
    cap_drop:
      - all
- name: Finer container restart/update control
  docker_container:
    name: test
    image: ubuntu:18.04
    env:
      arg1: "true"
      arg2: "whatever"
    volumes:
      - /tmp:/tmp
    comparisons: