making it so there are more options for notifications visibility (#315)

Author: Ryan Pfister

android/src/main/java/com/RNFetchBlob/RNFetchBlobReq.java

@@ -142,7 +142,12 @@ public void run() {
             if (options.addAndroidDownloads.getBoolean("useDownloadManager")) {
                 Uri uri = Uri.parse(url);
                 DownloadManager.Request req = new DownloadManager.Request(uri);
-                req.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
+                if(options.addAndroidDownloads.hasKey("notificationsEnum")) {
+                    req.setNotificationVisibility(options.addAndroidDownloads.getInt("notificationsEnum"));
+                }
+                else{
+                    req.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
+                }
                 if(options.addAndroidDownloads.hasKey("title")) {
                     req.setTitle(options.addAndroidDownloads.getString("title"));
                 }