Fix Sonar issue:

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

Change-Id: I4537e08936731ace55aeecb3ad941269ec1eb191
diff --git a/cli/src/main/java/org/onosproject/cli/net/DpisListCommand.java b/cli/src/main/java/org/onosproject/cli/net/DpisListCommand.java
index 85c2dda..0533652 100644
--- a/cli/src/main/java/org/onosproject/cli/net/DpisListCommand.java
+++ b/cli/src/main/java/org/onosproject/cli/net/DpisListCommand.java
@@ -214,7 +214,7 @@
 
     private void printDpiStatisticsJson(int number, DpiStatistics ds) {
         String index = number < 0 ? String.format("  -  ") : String.format("%5d", number);
-        if (ds.receivedTime().equals("")) {
+        if ("".equals(ds.receivedTime())) {
             print("ReceivedTime is null, No valid DPI Statistics!");
             return;
         }
@@ -233,7 +233,7 @@
             return;
         }
 
-        if (ds.receivedTime().equals("")) {
+        if ("".equals(ds.receivedTime())) {
             print("ReceivedTime is null, No valid DPI Statistics!");
             return;
         }
@@ -359,7 +359,7 @@
         sb.append(String.format(" [%s pkts/", fsi.packets()));
         sb.append(String.format("%s bytes]", fsi.bytes()));
         String serverHostName = fsi.hostServerName();
-        if (serverHostName != null && !serverHostName.equals("")) {
+        if (serverHostName != null && !"".equals(serverHostName)) {
             sb.append(String.format("[Host: %s]", serverHostName));
         }