Squashed revert of mms and eri overlays

Revert "overlay: remove Verizon specific eri.xml"

This reverts commit 5f92da62c686c12c00fc9f7948654816c586f838.

Revert "Add Japanese APNs/eri for au, docomo MVNO, EMOBILE and SoftBank"

This reverts commit eeeb0888d437ac0147cfe4b81aba264cf0d00b70.

Revert "Add apns/eri for Boost Mobile"

This reverts commit b207e2eda31e10a45a20774c61dc350975095d1b.

Revert "multi-carrier overlays: Add eri and config for US Cellular"

This reverts commit 1af75f1ba7abb351ec1113eeceaa00389a119e3b.

Revert "Multi-carrier overlays: Fix Mms"

This reverts commit f8b0737a435d211b01baf5df3feb9f98039884e2.

Revert "Generic multi-carrier overlays based on hammerhead"

This reverts commit 6f5758c9c33d1be82f76e32a8d83b427204436d1.
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