I tried this, it made no sense it didn't work, and it absolutely worked for me... Do it like this:
- Create a new APN
- Set Name field to "Dummy" (or something that fits what you need)
- Set the APN field to "dummy"
- Set APN type field to "default" (do not leave as Not Set)
- Press the overflow menu button (3 dots in the upper right corner) and select Save
The Device uses APN's in a priority and application order, the first ticked APN is considered the "primary" and if something needs access to a mobile network service, it looks in the active APN first for that type of service such as default (generic Internet), mms (picture messaging), supl (Secure User Plane location data), hipri (High Priority Mobile data, not sure how to explain this one), and fota (Firmware Over The Air, or OTA updates), if it finds the needed service in the default APN, it will use it, if it does not, it will go in a top down search order to try to find the proper match for the service. This is how some carriers can use one APN for Internet, and a different one for mms (not common, at least in the US). APN types "admin" or "vzwadmin" should not come into play here.
Note that in toggling back and forth, I could not get LTE to connect back up and the Moto G got stuck in HSPA+ mode, toggling in and out of Airplane restored LTE service though.
Oh, and although this isn't really the thread for it, I would recommend NOT ever having "admin" in any APN type field, this allows remote administration of your network connection.