Release heavier objects in teardown am: 5a3fd5faae

Change-Id: I06c6fae7f28025e065462e24f58d9cc4006a8ddb
diff --git a/tests/carservice_test/src/com/android/car/MockedCarTestBase.java b/tests/carservice_test/src/com/android/car/MockedCarTestBase.java
index f845972..729c32b 100644
--- a/tests/carservice_test/src/com/android/car/MockedCarTestBase.java
+++ b/tests/carservice_test/src/com/android/car/MockedCarTestBase.java
@@ -210,13 +210,16 @@
     public void tearDown() throws Exception {
         if (mCar != null) {
             mCar.disconnect();
+            mCar = null;
         }
         if (mCarImpl != null) {
             mCarImpl.release();
+            mCarImpl = null;
         }
         if (mMockIOInterface != null) {
             mMockIOInterface.tearDown();
         }
+        mMockedVehicleHal = null;
     }
 
     public CarPropertyService getCarPropertyService() {