Add debug logs to serialize method in FileSerializationUtil

Author: RovinKYK

components/org.wso2.carbon.identity.api.server.common/src/main/java/org/wso2/carbon/identity/api/server/common/file/FileSerializationUtil.java

@@ -63,6 +63,10 @@ public class FileSerializationUtil {
      */
     public static <T> FileContent serialize(T entity, String fileName, String fileType,
                                             FileSerializationConfig config) throws FileSerializationException {
+        if (LOG.isDebugEnabled()) {
+            LOG.debug(String.format("Serializing entity of type %s to file %s with type %s", 
+                    entity.getClass().getSimpleName(), fileName, fileType));
+        }
         if (config == null) {
             config = new FileSerializationConfig();
         }