Binding to dbus of Freedesktop not working

I’m creating a snap for the Gnome15 application. So far I have added all slots and permissions necessary to run the application. But some Dbus calls to ’ org.freedesktop.DBus.Introspectable’ and ‘org.freedesktop.DBus’ are not bind. When I run snappy-debug for checking the security logs I got following warnings:

= AppArmor =
Time: May 10 10:23:55
Log: apparmor=“ALLOWED” operation=“dbus_method_call” bus=“session” path="/modules/kwalletd5" interface=“org.freedesktop.DBus.Introsp
ectable” member=“Introspect” mask=“send” name=":1.367" pid=40016 label=“snap.gnome15.g15-desktop-service” peer_pid=40078 peer_label="
DBus access

= AppArmor =
Time: May 10 10:23:56
Log: apparmor=“ALLOWED” operation=“dbus_method_call” bus=“session” path="/org/freedesktop/DBus" interface=“org.freedesktop.DBus” mem
ber=“RequestName” mask=“send” name=“org.freedesktop.DBus” pid=40016 label=“snap.gnome15.g15-desktop-service” peer_label=“unconfined”
DBus access

The Gnome15 application logs are also showing errors:

Introspect error on :1.680:/modules/kwalletd5: dbus.exceptions.DBusException:
desktop.DBus.Error.NoReply: Message recipient disconnected from message bus without replying

The full snapcraft.yaml file can be found on Github.

Can someone help me with this to finalize the snap for the Gnome15 application?