Revert "Add a default MMS UA Profile URL"

This reverts commit f7059221427716f55d7ace0f71ab8e02b6c601cf.
Revert "Add a default MMS UA"

This reverts commit 1572bc97533fb216511035780a4e318f37e071ef.
Revert "Multi-carrier overlays: Fix Mms"

This reverts commit 51f94a45b826336060022f5d6785f2df419b6806.
Revert "Generic multi-carrier overlays based on hammerhead"

This reverts commit e4e2238cc69fa23d6c7ba7b9c0712bcd49448039.
Re-add apns from squashed revert

apns re-added from:
- Add apns/eri for Boost Mobile
- Add Japanese APNs/eri for au, docomo MVNO, EMOBILE and SoftBank

Change-Id: I2e0091cc4ed1a5c6957792940aba13b801bf7335

Conflicts:
	prebuilt/common/etc/apns-conf.xml