For better or worse the more correct name GNU/Linux did not catch on and is universally shortened to Linux. Android uses the Linux kernel, but is not GNU/Linux, and therefore is not Linux.
This is some ass-backwards logic. You’re trying to redefine Linux and then declaring that Android does not meet your novel definition. If Android, Alpine, and Chimera are not Linux, then what are they?
Most of what you said is exactly my point. It's true the word Linux, used properly, refers to a kernel and not an operating system. But that's not the way the word is used in practice, and it is not what OP meant when they used it. They meant " an OS with the Linux kernel and GNU userspace utilities." When the word Linux is used that way, Android is not Linux.
Do you not consider Alpine Linux to fall into the general category of "Linux", then? It lacks GNU user space utilities, though there is never a world where I would not consider it a "Linux" operating system. You seem to be overgeneralizing here and making assumptions about OP's intentions that aren't based in fact. I don't see the point in drawing meaningless lines, here. What you're referring to (as described by the GNU project) is GNU/Linux, not "Linux" by itself. The two are often but not always used interchangeably, and treating them as exactly the same leads to major outliers, like Alpine. I've heard plenty of people use the term "Linux" in practice to describe software running on embedded devices that don't contain GNU utilities, so this isn't exclusive to Alpine. In fact, the only real exception that I see consistently to operating systems that run the Linux kernel is Android, so it makes much more sense to formulate a description of the generic term "Linux" as simply having an exception for Android, though I'd argue that the only reasons that Android isn't viewed as "Linux" is because it is a mobile operating system, it is developed with the sole intention of including non-free, proprietary software (AOSP by itself isn't meant to be the full operating system on any device, but rather a framework), and the fact that the structure of the filesystem and the way apps are run differ completely from the ways of traditional "Linux". It seems to be an exception purely by the fact that it operates in fundamentally different ways than other "Linux" operating systems.
Idk (I'm not op) but I think when people say "can I install Linux on this" everyone knows they mean gnu/Linux. Yes, if I'm picking a container base image obviously alpine is also Linux, and if we're talking about kernels then Android is too. But if we're talking about desktop OSes then I think it's close enough.
Operating System Concepts by Silberschatz, Galvin and Gagne is a classic OS textbook. Andrew Tanenbaum has some OS books too. I really liked his OS Design and Implementation book but I'm pretty sure that one is super outdated by now. I have not read his newer one but it is called Modern Operating Systems iirc.
Sadly no, because while Android is based on Linux, it is so far removed that the kernel is wildly different. Some teams such as mobian, SFOS, postmarketOS, etc. have got fair dinkum Linux running on android devices though.
Firstly humans having lizard brains is pop science nonsense, and secondly humans and lizards are amniotes. And thirdly, the Android userland is Apache 2.0 licensed, regardless of whatever proprietary apps might or might not be installed on top of it, and the vast majority of Linux distros’ kernels have proprietary binary blob drivers installed in them.