When you call ApplyEditsAsync, your pending local edits are sent to the server database. There is no rollback. If you're not confident in your changes, don't apply the edits yet.
After that point, you'd have to apply opposite edits manually (ie Delete a feature you added, edit attributes to their old state etc).
Otherwise you'd have to set up versioned databases and maintain your versions serverside and only expose a specific version for users to edit, then control rollback/merging in the backoffice.
