OneNote for Android already allows users to view their password protected sections. However, users cannot set password for their notes on an Android device, instead they will have to set passwords for their notes using an OneNote desktop app. Based on the user feedback, Microsoft will soon allow users to add a password to a section to keep their notes from prying eyes.
To make it convenient for users to open their password protected sections, Microsoft will allow users to use their fingerprint to unlock their notes. Microsoft is currently testing this feature with OneNote Insiders, expect this feature to hit the Play Store for general consumers in the coming weeks.
Update the app here from Play Store.