Yeah, I've never heard of having to use Java 8 before. But Java6 is version 1.6. This is not device specific but it's common with all ROMs. See here: https://github.com/Octo-Kat/platform_build/blob/919306f64892e8a96053cc2fe520fdc136594878/core/main.mk#L163
So if you want you can check some of...