While this may be convoluted, this is how I stream a non apple device to the HomePod. On my windows laptop, I am running a program called airserver. It basically allows my laptop to act as an Apple TV. I can then airplay whatever to and from the laptop. I can also play audio off the laptop through the HomePod using airserver as it allows me to connect to it as an audio device. Today I had a friend connect his android phone via bluetooth to my laptop as a target for audio playback to stream from his phone. It then played through the HomePod. While this may not be an ideal setup, it does work.