adding file Name parameter

components/mobile-plugins/android-plugin/org.wso2.carbon.device.mgt.mobile.android.api/src/main/java/org/wso2/carbon/mdm/services/android/bean/wrapper/FileTransfer.java

@@ -45,7 +45,7 @@ public class FileTransfer extends AndroidOperation implements Serializable {
         return fileName;
     }
 
-    public String setFileName(String fileName){
+    public void setFileName(String fileName){
         this.fileName = fileName;
     }