As of 2017, the vision of the Internet of things has evolved due to a convergence of multiple technologies, including real-time analytics, commodity sensors, and embedded systems. But the actual idea of connected devices had been around longer, at least since the world’s first wireless computer communication network, ALOHAnet became operational in June 1971. In those days, the idea was often called “embedded internet” or “pervasive computing”.
Android Things (code-named Brillo) is aimed to be used with low-power and memory constrained devices, which are usually built from different platforms. It lets you build professional, mass-market products on a trusted platform, without doing the whole thing yourself. To flash Android Things onto your development board, download the latest preview image and follow the instructions.
While Buildroot itself will build most host packages it needs for the compilation, certain utilities (WSL) are expected to be already installed on the host system. If you have an Apple macOS or a Windows PC, you might also consider using the Yocto Project. It allows you to build and boot a custom embedded Linux image with the interface using a non-Linux development system. Beware of toolchains or distributions that are not maintained. In any case, you should make the choice according to your development board, and then be consistent in its use throughout the project.