Moved duplicated isUpdateAcceptable method to IntentData
and wrote a unit test for it.

Change-Id: I8b38476c41fba70abbba7ed0b37364696f17966d
diff --git a/core/api/src/test/java/org/onosproject/net/intent/IntentTestsMocks.java b/core/api/src/test/java/org/onosproject/net/intent/IntentTestsMocks.java
index 14abd83..8bef293 100644
--- a/core/api/src/test/java/org/onosproject/net/intent/IntentTestsMocks.java
+++ b/core/api/src/test/java/org/onosproject/net/intent/IntentTestsMocks.java
@@ -454,9 +454,8 @@
                 return -1;
             }
             MockTimestamp that = (MockTimestamp) o;
-            return (this.value > that.value ? -1 : (this.value == that.value ? 0 : 1));
+            return this.value - that.value;
         }
     }
 
-
 }