You don't have to transfer ownership of the apps. I'm not 100% certain but I believe that you can just login to the phone with both your real account and the Cloud Identity account, install the apps from the Play Store using the Cloud Identity account, and once they're installed you can use them with either account. That's how it works with other Google accounts. And of course you only need to do this with paid apps previously owned by the Cloud Identity account. New apps or free apps you can just get in your real account.