Add uptimes to device and cluster REST APIs

Change-Id: I0ccdf4e33135be4bcfd1674a76ff4b39e992268b
diff --git a/core/common/src/main/java/org/onosproject/codec/impl/ControllerNodeCodec.java b/core/common/src/main/java/org/onosproject/codec/impl/ControllerNodeCodec.java
index f6206b9..07d8e45 100644
--- a/core/common/src/main/java/org/onosproject/codec/impl/ControllerNodeCodec.java
+++ b/core/common/src/main/java/org/onosproject/codec/impl/ControllerNodeCodec.java
@@ -40,7 +40,9 @@
                 .put("id", node.id().toString())
                 .put("ip", node.ip().toString())
                 .put("tcpPort", node.tcpPort())
-                .put("status", service.getState(node.id()).toString());
+                .put("status", service.getState(node.id()).toString())
+                .put("lastUpdate", Long.toString(service.getLastUpdatedInstant(node.id()).toEpochMilli()))
+                .put("humanReadableLastUpdate", service.localStatus(node.id()));
     }