Add oci managed terraform + create snet module

oci-managed/snet/variables.tf

@@ -0,0 +1,16 @@
+variable "compartment_ocid" {}
+variable "vcn_id" {}
+variable "vcn_nat_route_id" {
+  type = string
+}
+variable "vcn_ig_route_id" {
+  type = string
+}
+
+variable "cluster_name" {
+  type = string
+}
+
+variable "environment" {
+  default = "prod"
+}