I'm under the impression that Android devices have had optional full disk encryption[0] for a long time, and that encryption isn't dependent upon cloud synchronization.
The plan was to have it enabled by default but that decreased disk performance drastically because of limitations of the encryption hardware. So they scrapped that plan, and its now only an option. Since it was optional, I doubt a majority of users looked at it, let alone enabled it. That's probably why Android doesn't figure in these discussions at all.
Having said that, high-end devices [1] from Marshmallow onward (6.0+) are supposed to have encryption enabled by default, according to the Android Compatibility Definition Document [2] so we'll probably see Android playing a bigger role in the encryption debate in the future. Budget phones are exempt from the requirement.
[1] - For device implementations supporting full-disk encryption and with Advanced Encryption Standard (AES) crypto performance above 50MiB/sec
Having said that, high-end devices [1] from Marshmallow onward (6.0+) are supposed to have encryption enabled by default, according to the Android Compatibility Definition Document [2] so we'll probably see Android playing a bigger role in the encryption debate in the future. Budget phones are exempt from the requirement.
[1] - For device implementations supporting full-disk encryption and with Advanced Encryption Standard (AES) crypto performance above 50MiB/sec
[2] - http://static.googleusercontent.com/media/source.android.com... Full Disk Encryption (section 9.9)