DefaultDeviceDescription and DefaultLinkDescriptionTest classes toString() method have been updated.
Annotation information of these classes is added to return value of toString() method. Unit tests have been updated.

Change-Id: I1d618eeb414b1ccad3588b36dad1ec0be0521c6a
diff --git a/core/api/src/main/java/org/onosproject/net/device/DefaultDeviceDescription.java b/core/api/src/main/java/org/onosproject/net/device/DefaultDeviceDescription.java
index 9074792..106c6c9 100644
--- a/core/api/src/main/java/org/onosproject/net/device/DefaultDeviceDescription.java
+++ b/core/api/src/main/java/org/onosproject/net/device/DefaultDeviceDescription.java
@@ -130,6 +130,7 @@
                 .add("uri", uri).add("type", type).add("mfr", manufacturer)
                 .add("hw", hwVersion).add("sw", swVersion)
                 .add("serial", serialNumber)
+                .add("annotations", annotations())
                 .toString();
     }