Now when I go to "Channel" in the android wallet I can see my channel there that appears as "FUNDED" and has the according balance displayed. However right above I still have "you can send m0 BTC; you can receive 0 mBTC". So somehow the channel is imported to my android wallet but it is not usable?
You very likely imported some kind of backup which allows you only to close that channel. How did you exactly export your Lightning channel?
By the way, you should be extremely careful when using the same Lightning Network channel on more than one device. In fact, you should never do this. At some point, any of your devices might have an outdated state of the channel which would force the other party to close the channel uncooperatively.
