-snip- and the lightning channel is shown, but with capacity 0.
How do i use the same lightning channel from both desktop and mobile?
As far as I know, it isn't possible.
Once you've done a transaction using the other, the other one will be outdated and could end up being closed or worse, penalized by the other end of the channel if you try to force-close it.
-snip- but there is no such option in mobile app on Android (is it removed?)
I haven't explored the Android app's lightning feature but I can't find it in my Android Electrum either.