An 'Edited' attribute is set when any type of edit is made to an image which then means it is easy to quickly filter for edited images, but once you've edited a photo there appears to be no way to reset it. I've tried all the reset options in the ios version of LrCC and also on the desktop version (restore to original). It doesn't matter what I try the image still has the edit attribute set. Hopefully this can be fixed.
Updates to the Adobe Photography Products were released today and contain a fix for this issue. Please install the update via your Creative Cloud Desktop App or your respective App Store. Note: You may need to refresh the Creative Cloud App for desktop software to show an update available. ([Ctrl/Cmd]+[Alt/Opt]+ [ R ]) For Mobile downloads, it may take several days for the update to appear in your respective App Stores. Thank you for your patience.