Merge "Do not allow editing of mcc, mnc for carrier id APNs" am: dbe7baa084 am: 27dbc6ed2a

Original change: https://android-review.googlesource.com/c/platform/packages/apps/Settings/+/2005870

Change-Id: Ia5c57252e2c6eba348b5ad89e63c49cd03e8e9d3