### Summary

when i use ansible systemd module, but the result is different between using systemd module and not using systemd module. 


```
 - name: using systemd module
    systemd:
      name: my.service
      state: stopped
      enabled: no
```

```
- name: using just command stop
  command: systemctl stop my.service

- name: using just command disable
  command: systemctl disable my.service
```
In Detail, my.service's killMode is process (KillMode=process), so if i stop my.service, another process in my.service cgroup  are not killed.  but when i use systemd module to stop and disable,  all process in my.service cgroup are killed 

### Issue Type

Bug Report

### Component Name

systemd

### Ansible Version

```console
$ ansible --version
ansible [core 2.11.10] 
  config file = /Users/kakao_ent/cloudms/git_ms/msg-deploy/ansible/ansible.cfg
  configured module search path = ['/Users/kakao_ent/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /Users/kakao_ent/cloudms/git_ms/msg-deploy/ansible/env/lib/python3.7/site-packages/ansible
  ansible collection location = /Users/kakao_ent/.ansible/collections:/usr/share/ansible/collections
  executable location = env/bin/ansible
  python version = 3.7.8 (v3.7.8:4b47a5b6ba, Jun 27 2020, 04:47:50) [Clang 6.0 (clang-600.0.57)]
  jinja version = 3.1.1
  libyaml = True
```


### Configuration

```console
# if using a version older than ansible-core 2.12 you should omit the '-t all'
$ ansible-config dump --only-changed -t all
```


### OS / Environment

Ubuntu 18.04

### Steps to Reproduce

1. not working task
```
 - name: using systemd module
    systemd:
      name: my.service
      state: stopped
      enabled: no
```

2. working task
```
- name: using just command stop
  command: systemctl stop my.service

- name: using just command disable
  command: systemctl disable my.service
```

and the service file attribute have to add like this

`KillMode=process`



### Expected Results

same as summary

### Actual Results

```console
same as summary
```


### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
(rc, out, err) = module.run_command("%s is-enabled '%s' -l" % (systemctl, unit))
            
            if rc == 0:
                enabled = True
                
                if out.splitlines() == ["indirect"] or out.splitlines() == ["alias"]:
                    enabled = False
            elif rc == 1:
                
                if module.params['scope'] == 'system' and \
                        is_initd and \
                        not out.strip().endswith('disabled') and \
                        sysv_is_enabled(unit):
                    enabled = True
            
            result['enabled'] = enabled
            
            if enabled != module.params['enabled']:
                result['changed'] = True
                if not module.check_mode:
                    (rc, out, err) = module.run_command("%s %s '%s'" % (systemctl, action, unit))
                    if rc != 0:
                        module.fail_json(msg="Unable to %s service %s: %s" % (action, unit, out + err))
                result['enabled'] = not enabled
        
        if module.params['state'] is not None:
            fail_if_missing(module, found, unit, msg="host")
            
            result['state'] = module.params['state']