Update [March 29, 2017]: The Carrier Services app received an update today to version 2.1.166 which brings along a major improvement. RCS or Rich Communication Services is now made more reliable by enabling enhanced network service. But bear in mind that RCS is limited to only certain carriers at the moment.

The Carrier Services app by Google has received a new update that allows users to control Wi-Fi calling features. This app mainly helps carriers to provide new networking capabilities to the users.

A user on Reddit noticed that after updating to the latest version 2.1.166 of the Carrier Services app, some new settings for Wi-Fi calling appeared. You can now enable or disable Wi-Fi calling, and also choose between Cellular or Wi-Fi. This is a pretty useful feature, and can help users save data when on Cellular, by selecting the Wi-Fi only option.

Not everyone has received the update yet, and not all devices seem to be supported. Devices and carriers that support Wi-Fi calling, or about to get support, will have this new feature. Perhaps Google is only testing this new feature as of now.

The Google Carrier Services app also supports the new RCS messaging features for Android Messages. However, you can only use this with carriers that support this feature. Have you received the update yet? 

via Reddit