Upgrade Atomix to 2.0.8 and simplify consistent primitive operation/event IDs

Change-Id: I33b68a134a7f3d016a8947bffc3cea0b90bd4bd2
diff --git a/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/AtomixWorkQueueEvents.java b/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/AtomixWorkQueueEvents.java
index 019290f..5458300 100644
--- a/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/AtomixWorkQueueEvents.java
+++ b/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/AtomixWorkQueueEvents.java
@@ -23,17 +23,11 @@
  * Atomix work queue events.
  */
 public enum AtomixWorkQueueEvents implements EventType {
-    TASK_AVAILABLE("taskAvailable");
-
-    private final String id;
-
-    AtomixWorkQueueEvents(String id) {
-        this.id = id;
-    }
+    TASK_AVAILABLE;
 
     @Override
     public String id() {
-        return id;
+        return name();
     }
 
     public static final KryoNamespace NAMESPACE = KryoNamespace.newBuilder()