Update mmv1/third_party/terraform/website/docs/d/compute_region_instance_template.html.markdown

Co-authored-by: Stephen Lewis (Burrows) <[email protected]>

Author: karolgorc

mmv1/third_party/terraform/website/docs/d/compute_region_instance_template.html.markdown

@@ -111,7 +111,7 @@ The following arguments are supported:
 
 * `confidential_instance_config` - Enable [Confidential Mode](https://cloud.google.com/compute/confidential-vm/docs/about-cvm) on this VM. Structure is [documented below](#nested_confidential_instance_config)
 
-* `key_revocation_action_type` - (optional) Action to be taken when a customer's encryption key is revoked.
+* `key_revocation_action_type` - Action to be taken when a customer's encryption key is revoked.
 
 <a name="nested_disk"></a>The `disk` block supports: