<!--- Verify first that your feature was not already discussed on GitHub -->
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##### SUMMARY
<!--- Describe the new feature/improvement briefly below -->
Currently it's not possible to specify disks to be included in the snapshot, always all disks are used.

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
ovirt_snapshot

##### ADDITIONAL INFORMATION
<!--- Describe how the feature would be used, why it is needed and what it would solve -->

<!--- Paste example playbooks or commands between quotes below -->
Could look like:
```yaml
ovirt_snapshot:
  description: My snap
  vm_name: myvm
  disks:
    - id: 123
    - id: 456
```

or 

```yaml
ovirt_snapshot:
  description: My snap
  vm_name: myvm
  disks:
    - name: myvm_disk_db
    - name: myvm_disk_store
```

<!--- HINT: You can also paste gist.github.com links for larger files -->

module.params['snapshot_id']
    )
    snapshot = get_entity(snapshot_service)
    if snapshot is None:
        raise Exception(
            "Snapshot with id '%s' doesn't exist" % module.params['snapshot_id']
        )
    if snapshot.snapshot_status != otypes.SnapshotStatus.IN_PREVIEW:
        if not module.check_mode:
            snapshot_service.restore(
                restore_memory=module.params.get('use_memory'),
            )
        changed = True
    else:
        if not module.check_mode:
            vm_service.commit_snapshot()
        changed = True
    if changed:
        wait(
            service=snapshot_service,
            condition=lambda snap: snap.snapshot_status == otypes.SnapshotStatus.OK,
            wait=module.params['wait'],
            timeout=module.params['timeout'],
        )
    return {
        'changed': changed,
        'id': snapshot.id if snapshot else None,
        'snapshot': get_dict_of_struct(snapshot),
    }
def get_snapshot_disk_id(module, snapshots_service):