Choose button remains disabled unless files are chosen from filepicker
Choose button remains disabled unless files are chosen
from filepicker

This is will help user to understand that you can only
click choose button once the files are selected from the
file picker. This addresses the solution for issue 16106

Signed-off-by: Sujith Haridasan <159bb8b76de959902b7336a61071ce5d5b381091@mentor.com>

IljaN/core,pollopolea/core,sharidas/core,sharidas/core,IljaN/core,owncloud/core,owncloud/core,IljaN/core,sharidas/core,pollopolea/core,IljaN/core,pollopolea/core,pollopolea/core,owncloud/core,pollopolea/core,phil-davis/core,IljaN/core,owncloud/core,sharidas/core,sharidas/core,owncloud/core