Fix vpn membership test

Author: danischm

gen/definitions/generic/vpn_membership_policy_definition.yaml

@@ -33,6 +33,7 @@ attributes:
         id: true
         description: Site list ID
         example: e858e1c4-6aa8-4de7-99df-c3adbf80290d
+        test_value: sdwan_site_list_policy_object.sites1.id
       - tf_name: site_list_version
         tf_only: true
         type: Version
@@ -43,8 +44,28 @@ attributes:
         type: ListString
         description: VPN list IDs
         example: '["04fcbb0b-efbf-43d2-a04b-847d3a7b104e"]'
+        test_value: "[sdwan_vpn_list_policy_object.vpns1.id]"
       - tf_name: vpn_list_versions
         tf_only: true
         type: Versions
         description: VPN list versions
         exclude_test: true
+
+test_prerequisites: |
+  resource "sdwan_site_list_policy_object" "sites1" {
+    name = "TF_TEST"
+    entries = [
+      {
+        site_id = "100-200"
+      }
+    ]
+  }
+
+  resource "sdwan_vpn_list_policy_object" "vpns1" {
+    name = "TF_TEST"
+    entries = [
+      {
+        vpn_id = "100-200"
+      }
+    ]
+  }