Merge pull request #12078 from AriParkkila/cell-ppp-ip

Cellular: Add PPP/IP config flags in CellularInterface.json

Author: 0xc0170

tools/test_configs/CellularInterface.json

@@ -36,7 +36,9 @@
             "nsapi.dns-response-wait-time": 30000,
             "cellular.use-apn-lookup": false,
             "lwip.ipv4-enabled": true,
+            "ppp.ipv4-enabled": true,
             "lwip.ipv6-enabled": true,
+            "ppp.ipv6-enabled": true,
             "lwip.tcp-enabled": true,
             "lwip.ppp-enabled": true,
             "lwip.ethernet-enabled": false,