gcp_compute_disk shows service account not implemented

Archives Ansible Project
1 
ansible --version
ansible 2.7.12
  config file = /etc/ansible/ansible.cfg
  configured module search path = ['/root/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/local/lib/python3.6/dist-packages/ansible
  executable location = /usr/local/bin/ansible
  python version = 3.6.9 (default, Apr 18 2020, 01:56:04) [GCC 8.4.0]


python --version
Python 3.6.9


- name: create a disk
  gcp_compute_disk:
    name: test_object
    size_gb: 50
    disk_encryption_key:
      kms_key_name: 
    zone: us-central1-a
    project: test_project
    auth_kind: serviceaccount
    scopes: 
        - https://www.googleapis.com/auth/compute
    state: present
 delegate_to: localhost
SUMMARY

fatal localhost unsupported parameter for (gcp_compute_disk) module kmsKeyName found in disk_encryption_key suuported parameter raw_key,sha 256

if i do comment disk_envryption_part then it says credential type none not implemented
or
credential type serviceaccount not implemented

ISSUE TYPE- Bug Report
COMPONENT NAME

gcp_compute_disk

ANSIBLE VERSION
ansible --version
ansible 2.7.12
  config file = /etc/ansible/ansible.cfg
  configured module search path = ['/root/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/local/lib/python3.6/dist-packages/ansible
  executable location = /usr/local/bin/ansible
  python version = 3.6.9 (default, Apr 18 2020, 01:56:04) [GCC 8.4.0]
CONFIGURATION
- name: create a disk
  gcp_compute_disk:
    name: test_object
    size_gb: 50
    disk_encryption_key:
      kms_key_name: 
    zone: us-central1-a
    project: test_project
    auth_kind: serviceaccount
    scopes: 
        - https://www.googleapis.com/auth/compute
    state: present
 delegate_to: localhost
OS / ENVIRONMENT

ubuntu 18.04

- name: create a disk
  gcp_compute_disk:
    name: test_object
    size_gb: 50
    disk_encryption_key:
      kms_key_name: 
    zone: us-central1-a
    project: test_project
    auth_kind: serviceaccount
    scopes: 
        - https://www.googleapis.com/auth/compute
    state: present
 delegate_to: localhost
EXPECTED RESULTS

it should be successful with disk creation part

ACTUAL RESULTS

It gives following error

fatal localhost unsupported parameter for (gcp_compute_disk) module kms_key_name found in disk_encryption_key suuported parameter raw_key,sha 256

if i do comment disk_envryption_part then it says credential type none not implemented

or

credential type serviceaccount not implemented