Remediation

From Google Cloud CLI

1. Log in to the Google Cloud Console
2. Go to Compute Engine
3. Go to VM instances
4. Click on the Specific VM
5. Click EDIT
6. Unselect Enable connecting to serial ports below Remote access block.
7. Click Save

From Google Cloud Console

Use the following command to disable.

gcloud compute instances add-metadata {{instance-name}} \
    --zone={{zone}} \
    --metadata=serial-port-enable=false

or

gcloud compute instances add-metadata {{instance-name}} \
    --zone={{zone}} \
    --metadata=serial-port-enable=0