The only thing linux about android is the kernel, i wouldn’t call that a linux distro and it’s not even compatible with any others.
The only thing about Linux IS that its a kernel. Its not like BSD where all the tools get developed together and released in the same edition, Linux is a kernel, full stop. Anything built on top of the Linux kernel is a Linux distro.
Can you name something other than the kernel that would be considered an essential element of a Linux distro and not available on android or BSD?
Its always been GNU+Linux, even stallman acknowledged its a separate thing and distros without GNU or glibc do exist on desktop too.