I'm using the following method to create unique identifiers on Android: https://gist.github.com/shareme/2759664
This works fine, but when deleting the app, a new identifier is created which is undesirable.
How can I persist this unique identifier across uninstall / reinstall but still have one UUID per device a user has.
I've researched multiple things already, but didn't find a clean solution yet.
Bonus question: Is this UUID-method really globally unique? Is it absolutely collision-safe?