If you found annoying the AT&T Address Book popup when you use Contacts then this tutorial is for you.
How to get rid of the AT&T address book popup
Somebody says that dialing at *#*#2666#*#* and setting Registration to Completed, disables the AT&T address book popup.
This method is effective only if you are able to root your device.
Step 1: Make sure that your device is rooted, if not then try searching on our site How to root your device.
Step 3: Enable the root directory. In ES File Explorer go to Menu > Settings, check Up to Root then below check Root Explorer. Accept any Superuser requests.
Step 4: Head to: system/csc/feature.xml and find the line in which states: <CscFeature_Contact_EnableAAB>true
Step 5: Change the true state to false, then Save the file and reboot your device.