terraform/gcp: Allow to change extra disk types (#8524)

contrib/terraform/gcp/variables.tf

@@ -49,6 +49,11 @@ variable "master_preemptible" {
   default = false
 }
 
+variable "master_additional_disk_type" {
+  type = string
+  default = "pd-ssd"
+}
+
 variable "worker_sa_email" {
   type    = string
   default = ""
@@ -64,6 +69,11 @@ variable "worker_preemptible" {
   default = false
 }
 
+variable "worker_additional_disk_type" {
+  type = string
+  default = "pd-ssd"
+}
+
 variable ssh_pub_key {
   description = "Path to public SSH key file which is injected into the VMs."
   type        = string