Add test for CM#[add|remove]DefaultNetworkActiveListener

Bug: 199753782
Test: atest FrameworksNetTests CtsNetTestCases
Change-Id: I2520f7f5feef61502479767aa023e281d1335ee4
diff --git a/tests/unit/java/android/net/ConnectivityManagerTest.java b/tests/unit/java/android/net/ConnectivityManagerTest.java
index e7873af..0914492 100644
--- a/tests/unit/java/android/net/ConnectivityManagerTest.java
+++ b/tests/unit/java/android/net/ConnectivityManagerTest.java
@@ -37,6 +37,8 @@
 import static android.net.NetworkRequest.Type.TRACK_DEFAULT;
 import static android.net.NetworkRequest.Type.TRACK_SYSTEM_DEFAULT;
 
+import static com.android.testutils.MiscAsserts.assertThrows;
+
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
@@ -314,6 +316,19 @@
     }
 
     @Test
+    public void testDefaultNetworkActiveListener() throws Exception {
+        final ConnectivityManager manager = new ConnectivityManager(mCtx, mService);
+        final ConnectivityManager.OnNetworkActiveListener listener =
+                mock(ConnectivityManager.OnNetworkActiveListener.class);
+        assertThrows(IllegalArgumentException.class,
+                () -> manager.removeDefaultNetworkActiveListener(listener));
+        manager.addDefaultNetworkActiveListener(listener);
+        verify(mService, times(1)).registerNetworkActivityListener(any());
+        manager.removeDefaultNetworkActiveListener(listener);
+        verify(mService, times(1)).unregisterNetworkActivityListener(any());
+    }
+
+    @Test
     public void testArgumentValidation() throws Exception {
         ConnectivityManager manager = new ConnectivityManager(mCtx, mService);