Get original file name when downloading inside WebView in Android
https://hocdelamduocviec.blogspot.com/2014/08/lay-ten-file-goc-trong-khi-download.html
Trích từ chuỗi contentDisposition trong hàm onDownloadStart(String url, String userAgent,
String contentDisposition, String mimetype, long contentLength) khi implements DownloadListener
String contentDisposition, String mimetype, long contentLength) khi implements DownloadListener
