I was trying to integrate 4G Modem on iMX6dl running Android Oreo 8.0. but surprisingly the default BSP from nxp comes with WiFi-Only Device settings, which will not show any UI related settings for Mobile_Networks in status-bar also as well as Settings application also. When I added RIL source code, device was not even trying to Send AT commands. I have debugged for some time and found the solution for the same. Many people have queried about this on nxp community So i thought of sharing my work as below.
To enable Mobile_Network settings in Android UI two files have to changed namely
1. device/fsl/imx6/imx6.mk --> used to mention device has RIL support
2. device/fsl/sabresd_6dq/overlay/frameworks//base/core/res/res/values/config.xml --> used to Override the default config settings present is android frameworks. Android Frameworks, frameworks/base/core/res/res/values/config.xml file is superset of all settings which has support for everything. So when I commented overridden settings from overlay config.xml Mobile_networks settings re-appeared in Android UI and Device started to send AT commands to modem subsequently device got registered to Network also. I Have attached the patch and S.shots here.