PL-8906 Support Kryo serialization by default in the next platform version

modules/global/src/com/haulmont/cuba/security/global/UserSession.java

@@ -58,6 +58,14 @@ public class UserSession implements Serializable {
 
     protected transient Map<String, Object> localAttributes;
 
+    /**
+     * INTERNAL
+     * Used only for kryo serialization
+     */
+    public UserSession() {
+        localAttributes = new ConcurrentHashMap<>();
+    }
+
     /**
      * INTERNAL
      */