Fix repowerd and screen usr.bin.media-hub-server
Fixes apparmor errors
subj==unconfined msg='apparmor="DENIED" operation="dbus_method_call" bus="system" path="/com/canonical/Unity/Screen" interface="org.freedesktop.DBus.Introspectable" member="Introspect" mask="send" name="com.canonical.Unity.Screen" pid=3564 label="/usr/bin/media-hub-server" peer_pid=1691 peer_label="unconfined"
subj==unconfined msg='apparmor="DENIED" operation="dbus_method_call" bus="system" path="/com/lomiri/Repowerd" interface="org.freedesktop.DBus.Introspectable" member="Introspect" mask="send" name="com.lomiri.Repowerd" pid=3564 label="/usr/bin/media-hub-server" peer_pid=1691 peer_label="unconfined"