ONOS-1418 Fix for intermittent issue with app store.

Change-Id: I94cb818550825984ec5e70a82a772a6f3bae5b0d
diff --git a/core/common/src/main/java/org/onosproject/common/app/ApplicationArchive.java b/core/common/src/main/java/org/onosproject/common/app/ApplicationArchive.java
index 880a31b..ff3ad1d 100644
--- a/core/common/src/main/java/org/onosproject/common/app/ApplicationArchive.java
+++ b/core/common/src/main/java/org/onosproject/common/app/ApplicationArchive.java
@@ -346,7 +346,7 @@
      * @param appName application name
      * @return true if the app descriptor was updated
      */
-    private boolean updateTime(String appName) {
+    protected boolean updateTime(String appName) {
         return appFile(appName, APP_XML).setLastModified(System.currentTimeMillis());
     }