##### SUMMARY
If there's currently a container with image `repo/name:tag1` running (or created), and I change the `docker_container` image tag to `repo/name:tag2` (where this image hasn't been pulled yet), `docker_container` will not notice that the image changed and will not recreate the container.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
docker_container

##### ANSIBLE VERSION
```paste below
2.9.0
```

updated_container = container
        if self.parameters.comparisons['networks']['comparison'] != 'ignore' or container_created:
            has_network_differences, network_differences = container.has_network_differences()
            if has_network_differences:
                if self.diff.get('differences'):
                    self.diff['differences'].append(dict(network_differences=network_differences))
                else:
                    self.diff['differences'] = [dict(network_differences=network_differences)]
                for netdiff in network_differences:
                    self.diff_tracker.add(
                        'network.{0}'.format(netdiff['parameter']['name']),
                        parameter=netdiff['parameter'],
                        active=netdiff['container']
                    )
                self.results['changed'] = True
                updated_container = self._add_networks(container, network_differences)
        if (self.parameters.comparisons['networks']['comparison'] == 'strict' and self.parameters.networks is not None) or self.parameters.purge_networks:
            has_extra_networks, extra_networks = container.has_extra_networks()
            if has_extra_networks:
                if self.diff.get('differences'):
                    self.diff['differences'].append(dict(purge_networks=extra_networks))
                else:
                    self.diff['differences'] = [dict(purge_networks=extra_networks)]
                for extra_network in extra_networks:
                    self.diff_tracker.add(
                        'network.{0}'.format(extra_network['name']),
                        active=extra_network