update machine type in TestAccComputeRegionInstanceTemplate_AdvancedMachineFeatures (#15255)

Author: shuyama1

mmv1/third_party/terraform/services/compute/resource_compute_region_instance_template_test.go.tmpl

@@ -3646,7 +3646,7 @@ data "google_compute_image" "my_image" {
 resource "google_compute_region_instance_template" "foobar" {
   name         = "tf-test-instance-template-%s"
   region       = "us-central1"
-  machine_type = "c2-standard-2"
+  machine_type = "n2-standard-2"
 
   disk {
     source_image = data.google_compute_image.my_image.self_link