Google’s Fuchsia OS will not be running on a modified version of the Linux kernel. The new operating system will use a custom microkernel dubbed Zircon. Android apps will be able to run on the new OS via a custom version of Android’s Android Runtime (ART) Issue published to the AOSP website confirms that the ART version will not target specific hardware, and it will produce a platform-specific package with a.far extension. A lot of questions regarding Android apps are still unanswered regarding how will these apps blend with the new platform they will have to run.
Source: https://www.bleepingcomputer.com/news/google/googles-new-fuchsia-os-to-support-android-apps/