The Fuchsia OS that Google is working on will be able to run Android apps. This is evident from changes in the Android Open Source Project. Fuchsia will run a special version of Android Runtime for support.
9to5Google previously found clues from the Android Open Source Project that referred to Fuchsia, but a recent readme file states that a version of ART, or Android Runtime, is being worked on for Fuchsia. The version will be installable via a far file, the equivalent of an apk file on Android.
Fuchsia is an operating system that Google is working on that is not based on Linux but on a micro-kernel developed by Google called Zircon. The existence of Fuchsia became known in 2016 and since then its operation has been demonstrated on multiple devices. It seems that Fuchsia should be able to run on a wide variety of devices, from embedded systems to smartphones, tablets and PCs. It is not clear whether Google wants to replace Android and/or Chrome OS with the OS or whether it should come out alongside the existing software.