title: Allow apk installation on all CPUs, with an ARM only lib in the app
body: <p>I'm building an Android app using some C++ features (through the NDK). These features are not mandatory (I have a slower fallback solution, not using the NDK). In order to keep the apk light, I'd like to build my ndk lib only for ARM, and use my fallback solution for other platforms.</p>
  
  <p>Is it possible to do that? If so, how? By default, if I provide my lib only for ARM, users running an x86 (for instance) device won't be able to install the app.</p>