added var for admin state as true

vars.tf

@@ -55,3 +55,9 @@ variable "enable-dhcp" {
   description = "whether dhcp in enabled. defualt is true"
   default = true
 }
+
+variable "admin_state_up" {
+  description = "whether admin state in enabled. defualt is true"
+  default = true
+}
+