codacy: Classes implementing Serializable should set a serialVersionUID

Signed-off-by: Andy Scherzinger <info@andy-scherzinger.de>

src/main/java/com/owncloud/android/operations/UploadException.java

@@ -21,6 +21,8 @@
 package com.owncloud.android.operations;
 
 class UploadException extends Exception {
+    private static final long serialVersionUID = 5931153844211429915L;
+
     UploadException() {
         super();
     }