Merge changes I22d67a7e,Ida4a4bc7,Ie8522862,Id55d8d6c into main

* changes:
  Ensure nri is satisfied before returning.
  Add testLockdownVpn that mocks platform VPN.
  Make variables in testLegacyLockdownVpn() final.
  Update testLegacyLockdownVpn to mock VPN.

service/src/com/android/server/ConnectivityService.java

@@ -8034,6 +8034,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
                 }
             }
         }
+        if (!highestPriorityNri.isBeingSatisfied()) return null;
         return highestPriorityNri.getSatisfier();
     }