> Android is free software in the sense that you can make and distribute modified versions.

I don't think that's enough to make it free software, and "free software in the sense..." is nonsensical. Free software would guarantee the continuance of that freedom. Since that guarantee doesn't exist, Google could place limitations on the Play Store at any time. The fact that they haven't makes the example less clear, but it doesn't make Android free software. Even Google doesn't claim that it is.