### Summary

Using docker_container_exec's stdin syntax doesn't decrypt vaulted variables.

I was suggested in https://github.com/ansible-collections/community.docker/issues/241 that it's most likely issue with Ansible, not the collection.

### Issue Type

Bug Report

### Component Name

docker_container_exec

### Ansible Version

```console
$ ansible --version
ansible [core 2.11.6]
  python version = 3.9.7 (default, Sep 10 2021, 14:59:43) [GCC 11.2.0]
  jinja version = 3.0.3
  libyaml = True
```


### Configuration

```console
$ ansible-config dump --only-changed
ANSIBLE_NOCOWS(/home/user/.ansible.cfg) = True
CACHE_PLUGIN(/home/user/.ansible.cfg) = jsonfile
CACHE_PLUGIN_CONNECTION(/home/user/.ansible.cfg) = /tmp/ansible-cachedir
CACHE_PLUGIN_TIMEOUT(/home/user/.ansible.cfg) = 5
DEFAULT_GATHERING(/home/user/.ansible.cfg) = smart
DEPRECATION_WARNINGS(/home/user/.ansible.cfg) = False
DIFF_ALWAYS(/home/user/.ansible.cfg) = True
HOST_KEY_CHECKING(/home/user/.ansible.cfg) = False
```


### OS / Environment

- Target: Ubuntu 20.04.3

### Steps to Reproduce

```yaml
    - name: Upload key
      community.docker.docker_container_exec:
        argv:
          - tee
          - secret.json
        container: '{{ docker_id }}'
        stdin: '{{ secret_data | to_json }}'
```

Var file (vaulted value is embedded):

```
secret_data:
  priv_key:
    value: !vault |
        $ANSIBLE_VAULT;1.1;AES256
        1161...
        ....
  pub_key:
    value: some_public_key
```

### Expected Results

Vaulted variable is properly decrypted.

I've tested encryption with:

```
ansible localhost -m ansible.builtin.debug -a var=secret_data -e @all/vars.yml
```

and the syntax is valid (variable is decrypted as expected), but not when using docker collection.

### Actual Results

```console
JSON file which was created consist ansible vault data, not decrypted string.

 below
"value": {"__ansible_vault": "$ANSIBLE_VAULT;1.1;AES256;\n1161...
```


### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
'''  value ? true_val : false_val '''
    if value is None and none_val is not None:
        return none_val
    elif bool(value):
        return true_val
    else:
        return false_val
def regex_escape(string, re_type='python'):
    string = to_text(string, errors='surrogate_or_strict', nonstring='simplerepr')
    '''Escape all regular expressions special characters from STRING.'''
    if re_type == 'python':
        return re.escape(string)
    elif re_type == 'posix_basic':
        
        
        return regex_replace(string, r'([].[^$*\\])', r'\\\1')
    
    
    
    
    elif re_type == 'posix_extended':
        raise AnsibleFilterError('Regex type (%s) not yet implemented' % re_type)
    else:
        raise AnsibleFilterError('Invalid regex type (%s)' % re_type)
def from_yaml(data):