Android uses the Linux kernel. Ubuntu for phones uses the Linux kernel. Jolla uses the Linux kernel. So not sure what you mean
While Android uses the Linux kernel, programs are actually written for the Dalvik platform. Ubuntu for phones on the other hand is a full GNU/Linux operating system, with most of the standard GNU/Linux libraries and programs. I haven't delved into Jolla beyond confirming it uses the Linux kernel, but I imagine it is more like Ubuntu for phones than Android.
You might be mixing up Ubuntu for Android
, which has been around for a while, and Ubuntu for phones
, which is just recently made public. While both run currently on phones that can or do also run Android, the former is a program on top of Android while the latter is an alternative to Android.
Anyway, Jolla uses RPM so I'm not going to go near it