[FIX] Google Messenger MMS topic

Many people have reported issues with MMS and the Google Messenger app.

I've tried a multitude of things, and the only thing that fixed it was to do the following:

Update APNs to the correct ones (in most cases, it will be nxtgenphone)

Code:

---

Name: AT&T Nextgenphone
APN: nxtgenphone
Proxy/Port/Username/Password/Server: Not set
MMSC: http://mmsc.mobile.att.net
MMS proxy: proxy.mobile.att.net
MMS port: 80
MCC: 310
MNC: 410
Authentication type: Not set
APN type: default,mms,supl,hipri,fota
APN protocol: IPv4
APN roaming protocol: IPv4
APN enable/disable: APN enabled
Bearer: Unspecified
MVNO type: none
MVNO value: Not set

---

Next - DELETE ALL UNUSED APNS. This is the part that fixed it for me, and a few others have reported it working as well. I'm not technically sure why it works, but deleting all unused APN's fixes MMS (sending + receiving) for Google Messenger.

I've tried new ROM's, APN settings, and even some resets, and this is the only fix I've found.

Google is aware of the MMS issue and it will likely be fixed soon, but this is an instant option to get MMS back!