Android system safety core is one Google recently secretly installed into a lot of devices (and likely coming to all) without any notice and you can only find it in the Play store if you have the direct link to it because it won't turn up in a search result. It will show up in a general Google search, which is how I found it. It looks to be dormant for the time being but will be used to scan content on your phone and incoming messages to auto censor stuff Google thinks you need to be protected from. The app info also claims any results will remain on your device.
Some people think it's a benign app. I think Google's current motto is no longer Don't Be Evil and now just Be Evil. I don't trust the app to remain innocent, nor private in light of the shadiness surrounding how it was installed so I've deleted it from my phone. It's safe to do so even if you simply just don't want it sitting there taking up space.