Fix out of tree build for the interface override files
Fix out of tree build for the interface override files

freedesktop-unofficial-mirror/gstreamer__gstreamer-sharp,Forage/gstreamer-sharp,gstreamer-sharp/gstreamer-sharp,freedesktop-unofficial-mirror/gstreamer__gstreamer-sharp,GStreamer/gstreamer-sharp,GStreamer/gstreamer-sharp,Forage/gstreamer-sharp,gstreamer-sharp/gstreamer-sharp,Forage/gstreamer-sharp,gstreamer-sharp/gstreamer-sharp,freedesktop-unofficial-mirror/gstreamer__gstreamer-sharp,Forage/gstreamer-sharp,GStreamer/gstreamer-sharp