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##### SUMMARY
<!--- Explain the problem briefly below -->
The [docker_container](https://docs.ansible.com/ansible/latest/modules/docker_container_module.html) module recreates a container when the `restart_policy` is changed. This can be changed using the `docker update` command.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
[docker_container](https://docs.ansible.com/ansible/latest/modules/docker_container_module.html)

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```shell
$ ansible --version
ansible 2.9.2
  config file = /etc/ansible/ansible.cfg
  configured module search path = ['/home/ingmar/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3.7/site-packages/ansible
  executable location = /usr/bin/ansible
  python version = 3.7.5 (default, Oct 17 2019, 12:09:47) [GCC 9.2.1 20190827 (Red Hat 9.2.1-1)]
```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```paste below
$ ansible-config dump --only-changed
<empty>
```

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. target OS versions, network device firmware, etc. -->
```shell
$ lsb_release -a
LSB Version:    :core-4.1-amd64:core-4.1-noarch
Distributor ID: Fedora
Description:    Fedora release 30 (Thirty)
Release:        30
Codename:       Thirty
```

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->
1. Run the following playbook:
```sh
$ ansible-playbook docker-container-update.yml
```
<!--- Paste example playbooks or commands between quotes below -->
```yaml
- name: Container update restart_policy
  hosts: localhost
  tasks:
    - name: Container with restart_policy
      docker_container:
        name: restart_policy_example
        image: alpine
        state: present
        restart_policy: unless-stopped
        entrypoint: top
```
2. Change the `restart_policy` to `always` and run it again.
```sh
$ ansible-playbook docker-container-update.yml
```
<!--- Paste example playbooks or commands between quotes below -->
```yaml
- name: Container update restart_policy
  hosts: localhost
  tasks:
    - name: Container with restart_policy
      docker_container:
        name: restart_policy_example
        image: alpine
        state: present
        restart_policy: unless-stopped
        entrypoint: top
```
3. Notice by using the `docker ps` command that the container is recreated instead of updated.

##### EXPECTED RESULTS
I expect the container to be update with  the new `restart_policy` by using the docker update command:
```sh
$ docker update --restart=<new policy>
``` 

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->
The container is recreated instead of updated.
I currently run a `command` task before the container which updates the command.
```yml
# Update docker restart policy
- name: Update docker container restart policy
  command: "docker update --restart={{ (restart_policy == false) | ternary('no', restart_policy) }} {{ container }}"
  ignore_errors: true
```
self.log('_get_expected_ulimits')
        if config_ulimits is None:
            return None
        results = []
        for limit in config_ulimits:
            results.append(dict(
                Name=limit.name,
                Soft=limit.soft,
                Hard=limit.hard
            ))
        return results
    def _get_expected_sysctls(self, config_sysctls):
        self.log('_get_expected_sysctls')
        if config_sysctls is None:
            return None
        result = dict()
        for key, value in config_sysctls.items():
            result[key] = str(value)
        return result
    def _get_expected_cmd(self):