I guess this needs more than the X-Sailjail/Permissions. You will also need to run your app under the privileged group, which is achieved with the help of mapplauncherd through the configuration in /usr/share/mapplauncherd/privileges.d/*.privileges - see also Mapplauncherd privileges question.
Additionally, if you want to see the contacts when you run your app from the IDE, check this Launching projects from SDK in sandboxed mode.