Add tests for NetworkMonitor isCaptivePortal

Bug: b/79499239
Test: added tests, ConnectivityService tests pass

Change-Id: I98d503b8f92d7f35e59dd1621a90f2eca8c7a63c

tests/net/java/com/android/server/ConnectivityServiceTest.java

@@ -880,7 +880,7 @@ public class ConnectivityServiceTest {
                 NetworkAgentInfo networkAgentInfo, NetworkRequest defaultRequest,
                 IpConnectivityLog log) {
             super(context, handler, networkAgentInfo, defaultRequest, log,
-                    NetworkMonitor.NetworkMonitorSettings.DEFAULT);
+                    NetworkMonitor.Dependencies.DEFAULT);
             connectivityHandler = handler;
         }