build: Do not install desktop files in $sysconfdir/xdg/autostart
build: Do not install desktop files in $sysconfdir/xdg/autostart

These files should not installed there by default. It's up to the
packager to install those desktop files there if the image built happens
to be a "media-explorer" image.

media-explorer/media-explorer,media-explorer/media-explorer,media-explorer/media-explorer,media-explorer/media-explorer