Extend plugin in order to support saving image/video files in
custom folder.
- Android:
 By default image will be saved at "pictures" system folder,
 and video at "movies" system folder.If user set folder name it will be
at root external storage.
- iOS:
 By default image and video will be saved at photos.
 If user set folder name it will be added as new album at photos.


CWF-443