This means it can't be used for actual production apps:
https://github.com/flutter/flutter/blob/master/packages/flutter_tools/lib/src/commands/apk.dart#L146

@stevenroose ran into this while trying to publish an app to the play store. See #1006

Should be pretty simple to fix. We should probably look for keys in the same directory and/or spit out a huge warning that we're using the chromium dev keys.

@jason-simmons