I have a dead simple Cordova app with a single plugin: org.apache.cordova.file.
When I emulate the app in an android emulator, the deviceready event is
deviceready
Try installing the 1.1.0 version of the file plugin. Updating to 1.2.0 was a bad idea.
cordova plugin add org.apache.cordova.file@1.1.0
This made the job for me on Android (and on iOS I stopped having other exotic problems).