201-confidential-vmss patch (#142)

* fix 201-confidential-vmss example

quickstart/201-confidential-vmss/variables.tf

@@ -1,15 +1,11 @@
-variable "admin_password" {
-  type        = string
-  sensitive   = true
-  description = "Admin password of the virtual machine scale set"
-}
-
 variable "location" {
   type        = string
+  default     = "westus"
   description = "Location where resources will be created"
 }
 
 variable "name_prefix" {
   type        = string
+  default     = "201-confidential-vmss"
   description = "Prefix of the resource name"
-}
+}