This apk (really, zip) contains dummy x86 and armeabi shared
libraries.  We include its contents in APKs compiled with support for
native exopackage; these APKs would otherwise contain no shared
libraries at all.  When an package contains no shared libraries at
all, Lollipop on an Aarch64 machine runs it in the 64-bit runtime (as
opposed to the 32-bit runtime), which is wrong because the libraries
we want to load later via native exopackage are all (at the time of
this writing) 32-bit libraries that cannot be loaded into a
64-bit process.

By including a few dummy 32-bit shared libraries, we convince the
system to run the program in 32-bit mode, allowing us to load our real
32-bit libraries later.

The libraries themselves are empty C files compiled with the Android
NDK gcc in -shared mode.  We've assembled them into the checked-in zip
file manually.