This has been already asked already on MSO, although without "official" answer. There's also this answer by Jeff Atwood (admittedly, two years old, and before creation of the diverse family of Area 51 sites) specifically on a question whether English-only policy should be in the FAQ:
Do we really need a NO ELEPHANTS sign?
I mean, isn't such a thing obvious? Would you go to a forum where everyone was communicating in French and type
Hey French Dudes, I got a question but I don't know French so I'm just going to go ahead and ask it in English anyway?
Note that this is different from Stack Overflow, where English is a strict requirement.
There doesn't seem to be a general consensus or an ex cathedra response, and it seems that it's up to each community to decide for themselves.
Although I can appreciate why people would want to be able to ask questions in other languages than English (I'm not a native English speaker either, nor even live in a country where English is an official language), allowing this on Android-SE is going to be a major PITA from pretty much any perspective -- moderation, quality, percentage answered questions, user participation -- for a small to negligible benefit.