When as JavaScript developer you need to do Java Android. And not the simple kind of tasks... I have 0 knowledge on the whole Android platform.. FML

A lot of good books can bring you up to speed fast. Your skills will translate. Also a lot of good tools like Titanium for cross platform.

See it as an opportunity to learn!

Oh you mean Java the frontend language recruiters keep telling me about.

Hit YouTube or something like Udemy. Either is pretty good

TeamTreehouse helped me. As well as just going through sample projects on Android dev forums (if you're doing an Android project.) By the way, the opposite is true for me. A co-worker had me look at JavaScript and I was like but what data type is this... what is this sorcery... I don't understand.