Found my saves in my rooted Noxplayer Android-Test-Environment here.
/data/data/org.godotengine.highschoolofsuccbus/files/saves
But you have only access there on a rooted Android System. You should be carefully to root your Android. You decrease the security level for your phone, loose any warranties, some other apps can refuse to work and updating your system could be more difficulty.
https://en.wikipedia.org/wiki/Rooting_(Android)
I will try to find a solution to get access to the saves without rooting by changing the manifest of HOS and try to define there that HOS should store it´s savefiles at a different place where we have access without rooting.