res/values-mcc460/config.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <!-- Network validation URL configuration for devices using a Chinese SIM (MCC 460).
         The below URLs are often whitelisted by captive portals, so they should not be used in the
         general case as this could degrade the user experience (portals not detected properly).
         However in China the default URLs are not accessible in general. The below alternatives
         should allow users to connect to local networks normally. -->
    <!-- default_captive_portal_https_url is not configured as overlayable so
         OEMs that wish to change captive_portal_https_url configuration must
         do so via configuring runtime resource overlay to
         config_captive_portal_https_url and *NOT* by changing or overlaying
         this resource. It will break if the enforcement of overlayable starts.
         -->
    <string name="default_captive_portal_https_url" translatable="false">https://connectivitycheck.gstatic.com/generate_204</string>
    <!-- default_captive_portal_fallback_urls is not configured as overlayable
         so OEMs that wish to change captive_portal_fallback_urls configuration
         must do so via configuring runtime resource overlay to
         config_captive_portal_fallback_urls and *NOT* by changing or overlaying
         this resource. It will break if the enforcement of overlayable starts.
         -->
    <string-array name="default_captive_portal_fallback_urls" translatable="false">
        <item>http://www.googleapis.cn/generate_204</item>
    </string-array>
</resources>