##### SUMMARY

The merge of #45507 broke `update_password="on_create"` on Alpine Linux with the shadow package installed.

This does not work anymore
```yml
  - name: add users                                                                                                                                                                                                                                  
    user:
      name: "{{ item.name }}"
      comment: "{ item.comment }}"
      shell: "/bin/zsh"
      password: '*'
      update_password: on_create
   with_items:
    ....
```

After the PR, all users that have a password that is not '*' will get their password changed.

Reverting bf3e397ea7922e8bd8b8ffbc05d1aede0317d119, makes 'update_password: on_create' work as expected again.

##### ISSUE TYPE
- Bug Report

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

lib/ansible/modules/system/user.py

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
2.8.7
```

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

```

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. target OS versions, network device firmware, etc. -->

Alpine Linux

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->

<!--- Paste example playbooks or commands between quotes below -->
```yaml
  - name: add users                                                                                                                                                                                                                                  
    user:
      name: "{{ item.name }}"
      comment: "{ item.comment }}"
      shell: "/bin/zsh"
      password: '*'
      update_password: on_create
```

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

##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->

Users that are not created does not get their password changed.

##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->

<!--- Paste verbatim command output between quotes -->
```paste below
Password "hash" changed to '*'
```

chunk = os.read(master_out_fd, 10240)
                            out_buffer += chunk
                            if prompt in out_buffer:
                                os.write(master_in_fd, to_bytes(self.ssh_passphrase, errors='strict') + b'\r')
                                prompt = second_prompt
                        else:
                            chunk = os.read(master_err_fd, 10240)
                            err_buffer += chunk
                            if prompt in err_buffer:
                                os.write(master_in_fd, to_bytes(self.ssh_passphrase, errors='strict') + b'\r')
                                prompt = second_prompt
                        if b'Overwrite (y/n)?' in out_buffer or b'Overwrite (y/n)?' in err_buffer:
                            
                            return (None, 'Key already exists', '')
                rc = p.returncode
                out = to_native(out_buffer)
                err = to_native(err_buffer)
            except OSError as e:
                return (1, '', to_native(e))
        else:
            cmd.append('-N')
            cmd.append('')
            (rc, out, err) = self.execute_command(cmd, data=overwrite)
        if rc == 0 and not self.module.check_mode:
            
            
            os.chown(ssh_key_file, info[2], info[3])
            os.chown('%s.pub' % ssh_key_file, info[2], info[3])
        return (rc, out, err)
    def ssh_key_fingerprint(self):