Apple doesn't own AAC. It is defined in Part 3 of the MPEG-4 standard, and was created by several companies and a research institute, not including Apple. Apple is just the earliest major player to adopt it.
What’s wrong with mp3s?
Old standard, less quality for the same bitrate, poor response at high frequencies, many other reasons. If a device doesn't play AAC, dump the device. You probably wouldn't want a modern media player that only played MPEG-1 or MPEG-2 video and couldn't support the modern codecs such as H.264 or VC-1. We have a word for that: obsolete.
But given that, I don't know of any Android devices that don't play AAC.
Yeah, my information was way out of date. I was stuck in a time when pretty much no one but Apple had adopted AAC -- and now I see that Archos, Creative, SanDisk, Sony, and even the Zune support it. Our little standard is all grown up.
I like mp3s and flacs and wavs. I might not have any aacs at all. I probably have around 100 gigs of mp3s wavs flacs. Is m4a aac? I have a few m4as.