[Nexus 6 Android Development] error311:
Yeah no problem. I tried a lot but I recently started to look back at commits from aosp: https://android.googlesource.com/device/moto/shamu/+/d379ed7cf428064f11a80e097826c5d92811ac07

I noticed xml-mcc311-mnc480 was actually a file not a folder, just create that folder and add this eri.xml:

<?xml version="1.0" encoding="utf-8"?>
<!--
/*
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
-->

<!-- Note that IconMode can be only 0, ON or 1, FLASHING
The icon is turned OFF if then IconIndex = 1 -->

<EriFile VersionNumber="5"
NumberOfEriEntries="19"
EriFileType="2">

<CallPromptId Id="0"
CallPromptText="CallPromptId0"/>

<CallPromptId Id="1"
CallPromptText="CallPromptId1"/>

<CallPromptId Id="2"
CallPromptText="CallPromptId2"/>

<EriInfo RoamingIndicator="0"
IconIndex="0"
IconMode="0"
EriText=""
CallPromptId="0"
AlertId="0"
DataServiceSupport="1"/>

<EriInfo RoamingIndicator="1"
IconIndex="1"
IconMode="0"
EriText=""
CallPromptId="0"
AlertId="0"
DataServiceSupport="1"/>

<EriInfo RoamingIndicator="2"
IconIndex="2"
IconMode="1"
EriText=""
CallPromptId="0"
AlertId="0"
DataServiceSupport="1"/>

<EriInfo RoamingIndicator="64"
IconIndex="1"
IconMode="0"
EriText="Verizon Wireless"
CallPromptId="0"
AlertId="0"
DataServiceSupport="1"/>

<EriInfo RoamingIndicator="65"
IconIndex="3"
IconMode="0"
EriText="Network Extender"
CallPromptId="0"
AlertId="0"
DataServiceSupport="1"/>

<EriInfo RoamingIndicator="66"
IconIndex="1"
IconMode="0"
EriText="Extended Network"
CallPromptId="0"
AlertId="4"
DataServiceSupport="0"/>

<EriInfo RoamingIndicator="67"
IconIndex="0"
IconMode="0"
EriText="Extended Network"
CallPromptId="0"
AlertId="4"
DataServiceSupport="0"/>

<EriInfo RoamingIndicator="68"
IconIndex="0"
IconMode="0"
EriText="Roaming"
CallPromptId="0"
AlertId="5"
DataServiceSupport="0"/>

<EriInfo RoamingIndicator="69"
IconIndex="2"
IconMode="0"
EriText="Extended Network"
CallPromptId="0"
AlertId="4"
DataServiceSupport="0"/>

<EriInfo RoamingIndicator="70"
IconIndex="2"
IconMode="0"
EriText="Roaming"
CallPromptId="0"
AlertId="5"
DataServiceSupport="0"/>

<EriInfo RoamingIndicator="71"
IconIndex="1"
IconMode="0"
EriText="Extended Network"
CallPromptId="0"
AlertId="4"
DataServiceSupport="1"/>

<EriInfo RoamingIndicator="72"
IconIndex="0"
IconMode="0"
EriText="Extended Network"
CallPromptId="0"
AlertId="4"
DataServiceSupport="1"/>

<EriInfo RoamingIndicator="73"
IconIndex="0"
IconMode="0"
EriText="Roaming"
CallPromptId="0"
AlertId="5"
DataServiceSupport="1"/>

<EriInfo RoamingIndicator="74"
IconIndex="2"
IconMode="0"
EriText="Extended Network"
CallPromptId="0"
AlertId="4"
DataServiceSupport="1"/>

<EriInfo RoamingIndicator="75"
IconIndex="2"
IconMode="0"
EriText="Roaming"
CallPromptId="0"
AlertId="5"
DataServiceSupport="1"/>

<EriInfo RoamingIndicator="76"
IconIndex="0"
IconMode="0"
EriText="Verizon Wireless"
CallPromptId="0"
AlertId="0"
DataServiceSupport="1"/>

<EriInfo RoamingIndicator="77"
IconIndex="2"
IconMode="0"
EriText="Verizon Wireless"
CallPromptId="0"
AlertId="0"
DataServiceSupport="1"/>

<EriInfo RoamingIndicator="78"
IconIndex="1"
IconMode="0"
EriText="Network Extender"
CallPromptId="0"
AlertId="1"
DataServiceSupport="1"/>

<EriInfo RoamingIndicator="79"
IconIndex="3"
IconMode="1"
EriText="Network Extender"
CallPromptId="0"
AlertId="1"
DataServiceSupport="1"/>

</EriFile>

That will fix Verizon overlay issue.