It is my opinion that Google does not view Android as simply "an operating system for phones". Android has tremendous application in IoT devices and appliances. The lifecycle of many applications is quite a bit longer than the cell phone.
The only two reasons people put up with android on phones are
1) it's the only choice if you want something small with a cell modem
2) it's the only choice if you want to run Snapchat
Android is incredibly aweful. It's actually impossible to write apps for it that won't crash. If you're writing firmware it's even worse! Have you ever tried to build it? It's a nightmare! The source for a basic system is over 60GB and has a crazy number of dependencies.
For embedded systems/IOT you're thousands of times better off just using buildroot or an RTOS.
As we see an increase in the diversity of applications using Android, this upgrade path will be very important. Just wait until you see your first ATM or POS system "Powered By Android ©".