Samsung is rolling out major OS update on its 2017 J-series devices, first Galaxy J3 then J5 and now the Galaxy J7 2017, which recently started receiving the Android 8.1 Oreo upgrade, skipping the Android 8.0 version.
The Android 8.1 Oreo update brings a lot of cool features such as Picture-in-Picture, Notification Dots, Autofill API, Revamped notifications center, etc.
According to theAndroidSoul, The Android 8.1 OTA update for Galaxy J7 2017 (SM-J730F) available as build number J730FMXXU4BRI3 alongside August 2018 security patch. The update currently rolling in Europian countries and expected to expanded as it proceeds. You can check the update manually via Settings > About Phone > Software Update.