I am able to make my app, the device owner app through NFC as mentioned here. Now I want to update my app over the air, but I couldn\'t find a method without rooting
I guess you might want to become an EMM/MDM partner app-it is similar to device owner app but with enhanced privileges and APIs. Normally OEMs like Samsung/HTC provides hidden APIs to the MDM partner apps for upgrading apps.I am not sure whether Android for Work also provides this api.
For eg: OEMs provides an api called updatePackage(String packageName) which can be use by MDM client on the device to update the package.You can use this API to update the Device Owner App too.