[macOs] File types are not recognized in media player when trying to open a file

Steps:

1. Open example 'Video Widget Example'

2. Make sure you have avi or wav file stored on the disk.

3. Click open button and select 'avi' from the dropdown list for supported files.

4. Try to select 'avi' file. Do the same for 'wav'.

Actual:  Cannot select the file.

Expected: User should be able to select the file. 

Note: See the attached video for more details It works well on Windows -> there are no filetypes specified - user can open 'All files'