Change the data type of Data Point value from Double to Object

Change-Id: If5243fcb25c9893601695743b562ce88b844c64d
diff --git a/core/api/src/test/java/org/onosproject/ui/chart/ChartUtilsTest.java b/core/api/src/test/java/org/onosproject/ui/chart/ChartUtilsTest.java
index 2252503..c770b7c 100644
--- a/core/api/src/test/java/org/onosproject/ui/chart/ChartUtilsTest.java
+++ b/core/api/src/test/java/org/onosproject/ui/chart/ChartUtilsTest.java
@@ -29,7 +29,7 @@
     private static final String BAR = "bar";
 
     private static final String ARRAY_AS_STRING =
-            "[{\"foo\":1.0,\"bar\":2.0},{\"foo\":3.0,\"bar\":4.0}]";
+            "[{\"foo\":\"1.0\",\"bar\":\"2.0\"},{\"foo\":\"3.0\",\"bar\":\"4.0\"}]";
     private static final String NODE_AS_STRING =
             "{\"dev1\":\"of:0000000000000001\",\"dev2\":\"of:0000000000000002\"}";