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##### SUMMARY
<!--- Describe the new feature/improvement briefly below -->
vmware_guest_disk should propose `disk_mode` parameter (like vmware_guest module).
The playbook bellow does not raise an error but disk is always added in `persistent` mode, even I set `independent_persistent` for `disk_mode` var.
If it's a bug please could you fix it? If it's not consider it as a feature request :)

##### ISSUE TYPE
- Feature Idea (or maybe a bug)

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

##### 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 -->
```yaml
---
- name: get vm {{ target | upper }} facts
  vmware_guest_facts:
    hostname: "{{ vcenter_hostname }}"
    username: "{{ vcenter_username }}"
    password: "{{ vcenter_password }}"
    datacenter: "{{ datacenter }}"
    validate_certs: no
    name: "{{ target | upper }}"
  register: vm_facts
  delegate_to: localhost

- name: add disk to vm {{ target | upper }}
  vmware_guest_disk:
    hostname: "{{ vcenter_hostname }}"
    username: "{{ vcenter_username }}"
    password: "{{ vcenter_password }}"
    datacenter: "{{ datacenter }}"
    validate_certs: no
    name: "{{ target | upper }}"
    disk:
      - size_gb: "{{ size_gb }}"
        type: "{{ type }}"
        disk_mode: "{{ disk_mode }}"
        scsi_controller: "{{ scsi_controller }}" 
        unit_number: "{{ unit_number }}"
        datastore: "{{ vm_facts.instance.hw_datastores | first }}"
  delegate_to: localhost
```

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

- The folder should include the datacenter. ESX's datacenter is ha-datacenter
     - 'Examples:'
     - '   folder: /ha-datacenter/vm'
     - '   folder: ha-datacenter/vm'
     - '   folder: /datacenter1/vm'
     - '   folder: datacenter1/vm'
     - '   folder: /datacenter1/vm/folder1'
     - '   folder: datacenter1/vm/folder1'
     - '   folder: /folder1/datacenter1/vm'
     - '   folder: folder1/datacenter1/vm'
     - '   folder: /folder1/datacenter1/vm/folder2'
     type: str
   datacenter:
     description:
     - The datacenter name to which virtual machine belongs to.
     required: True
     type: str
   use_instance_uuid:
     description:
     - Whether to use the VMware instance UUID rather than the BIOS UUID.
     default: no
     type: bool
     version_added: '2.8'
   disk:
     description:
     - A list of disks to add.
     - The virtual disk related information is provided using this list.
     - All values and parameters are case sensitive.
     - 'Valid attributes are:'
     - ' - C(size[_tb,_gb,_mb,_kb]) (integer): Disk storage size in specified unit.'