Fix Sonar issue:

Strings literals should be placed on the left side when checking for
equality

Change-Id: I4537e08936731ace55aeecb3ad941269ec1eb191
diff --git a/apps/yms/app/src/main/java/org/onosproject/yms/app/ytb/YdtBuilderFromYo.java b/apps/yms/app/src/main/java/org/onosproject/yms/app/ytb/YdtBuilderFromYo.java
index 4faa58b..76b1647 100644
--- a/apps/yms/app/src/main/java/org/onosproject/yms/app/ytb/YdtBuilderFromYo.java
+++ b/apps/yms/app/src/main/java/org/onosproject/yms/app/ytb/YdtBuilderFromYo.java
@@ -800,7 +800,7 @@
                 }
                 break;
             }
-            if (!val.equals("")) {
+            if (!"".equals(val)) {
                 leafListVal.add(val);
             }
         }