feat(oci): attempt to make servers provisioned

tf/oci_common_private_network/subnet.tf

@@ -5,4 +5,12 @@ resource "oci_core_subnet" "this" {
 
   display_name = oci_core_vcn.this.display_name
   dns_label    = "subnet"
+}
+
+locals {
+  subnet = oci_core_subnet.this
+}
+
+output "subnet_id" {
+  value = local.subnet.id
 }