Created attachment 4672 
make-open-with-dialog-resizable.patch

I see no reason why a user shouldn't be allowed to adjust the size of the chooser dialog. Other dialogs like the file properties are resizable too.

This is much better than having to scroll through the huge list of applications. Ideally, the dialog height would adjust itself in relation to the screen size, but since it will not be used that often, making it resizable would help a lot too.

Trivial patch attached.