Win port: Disable android_{stats,internal} at build time

Before this CL, the android_internal/android_stats code
was relying on:
1. Code building on all platforms, including mac, for the
   dlsym-based trampolines.
2. A constexpr to make the trampolines a no-op on non-android
   builds.

This CL instead just provides an alternative empty
implementation, removing the need for dlfcn.h

Bug: 174454879
Change-Id: Ie9167fe9b82d8fe7d5b49e6674116568ecc9607f