Change validation of kendo upload control dynamically

Question

Could you please help me how to change allowedExtensions valiation of kendo file upload control dynamically runtime using Jquery?

e.g. Suppose user select to upload the media file, then allowedExtensions should be change to ".mp4".

 $("#filesFromLocal").kendoUpload({
                success: PWonSuccess,
                upload: PWonUpload,
                error: PWonError,
                multiple: false,
                cache: false,
                contentType: false,
                processData: false,
                validation: {
                    allowedExtensions: [".pdf"],
                    maxFileSize: maxFileSize
                },
                async: {
                    saveUrl: saveURL,
                    chunkSize: chunkSize,
                    autoUpload: false
                },
                remove: function (e) {
                    var fileInfo = $("#filesFromLocal").data("kendoUpload").getFiles();
                    if (fileInfo.length == 2) {
                        LocalDeletedFile = false;
                    }
                    else {
                        LocalDeletedFile = true;
                    }
                },
                select: onimportselect
            });