Change the logic of synchronizing flow rules on kubevirt network

Change-Id: Iea95dfc0035e822b207d902ceecc49001ae66bbb
(cherry picked from commit f0d00d5e5dfd9576bdbfa826bc81cd168f0589b1)
diff --git a/apps/kubevirt-node/app/src/main/java/org/onosproject/kubevirtnode/util/KubevirtNodeUtil.java b/apps/kubevirt-node/app/src/main/java/org/onosproject/kubevirtnode/util/KubevirtNodeUtil.java
index 96c71d9..66b1af8 100644
--- a/apps/kubevirt-node/app/src/main/java/org/onosproject/kubevirtnode/util/KubevirtNodeUtil.java
+++ b/apps/kubevirt-node/app/src/main/java/org/onosproject/kubevirtnode/util/KubevirtNodeUtil.java
@@ -428,4 +428,17 @@
         }
         return null;
     }
+
+    /**
+     * Waits for the given length of time.
+     *
+     * @param timeSecond the amount of time for wait in second unit
+     */
+    public static void waitFor(int timeSecond) {
+        try {
+            Thread.sleep(timeSecond * 1000L);
+        } catch (Exception e) {
+            log.error(e.toString());
+        }
+    }
 }