How to skip the upgrade to Oreo My Galaxy S7 downloaded the Oreo upgrade, and now a notification persists in my status bar and every now and then it pops up asking me to upgrade. I don't want to upgrade. Is there a way to skip upgrading without rooting or factory reset? 
I tried deleting cache and disabling the software upgrade app but it didn't work, and there's no option to disable the app.
I solved the issue by buying Package Installer and disabling the Software Update app.