Android doesn't use autotools. They knew better than touch that mess. They use plain old makefiles. However, they do use GNU Make extensions. I have not used OpenWRT, so I don't know what build system they use.
> I'm not too old to learn something new, but I'm definitely too old to
> start pointless crusade with goal of total replacement of autotools with
> CMake. And world with a mix of autotools and CMake is much, much, worse
> then world of pure autotools.
We already live in a world with a mix of autotools and other things.
The kernel doesn't use autotools (which makes kernel hackers recommending autotools unintentionally ironic.) KDE uses CMake. MySQL is transitioning from autotools to CMake. Anything that is portable to Windows (like openoffice, the gimp, etc.) will need to have a parallel build system to handle that platform, because autotools can't.