Add display device as an option to gcp_compute_instance.py

##### SUMMARY

##### ISSUE TYPE
- Can we add display device option in the gcp compute instance module?

##### COMPONENT NAME

gcp_compute_instance.py

##### ADDITIONAL INFORMATION

This feature would be useful in the GCP console to see if the system is coming online or not. It allows for screen capture.

```yaml

name: Create an Instance
google.cloud.gcp_compute_instance:
state: present
name: "{{ machine_name | lower }}"
machine_type: "{{ machine_type }}"
zone: "{{ zone }}"
disks:
- auto_delete: true
boot: true
source: "{{ disk }}"
deletion_protection: "{{ deleteprotection }}"

```

Start by reading gcp_compute_instance.py and the existing instance options to see where a display-device setting belongs. Check the GCP compute instance API requirements for screen capture, then add the option so an instance can be created with a display device and verify that the resulting instance exposes the requested console screen-capture capability.

Written by the indexing model from the issue text.