Change the APIs to instantiate Resource and ResourceId

Now, DiscreteResource/DiscreteResourceId is provided by DiscreteFactory.
Similarly, ContinuousResource/ContinuousResourceId is provided by
ContinuousFactory. These factory instances can be obtained by static
factory method such as Resource.discrete(...) or Resource.continuous(...).

Change-Id: Ic94f7336c0e1f74cf2dddcac899de300362aff3e
diff --git a/core/net/src/test/java/org/onosproject/net/intent/impl/ObjectiveTrackerTest.java b/core/net/src/test/java/org/onosproject/net/intent/impl/ObjectiveTrackerTest.java
index 480e6e4..7c1036e 100644
--- a/core/net/src/test/java/org/onosproject/net/intent/impl/ObjectiveTrackerTest.java
+++ b/core/net/src/test/java/org/onosproject/net/intent/impl/ObjectiveTrackerTest.java
@@ -232,7 +232,7 @@
     @Test
     public void testResourceEvent() throws Exception {
         ResourceEvent event = new ResourceEvent(RESOURCE_ADDED,
-                Resource.discrete(DeviceId.deviceId("a"), PortNumber.portNumber(1)));
+                Resource.discrete(DeviceId.deviceId("a"), PortNumber.portNumber(1)).resource());
         resourceListener.event(event);
 
         assertThat(