Use ONC carrier info in JS

chromeos/test/data/network/translation_of_shill_cellular_with_state.onc

 {
   "Type": "Cellular",
   "Name": "Test Network",
   "Cellular": {
     "ActivationState": "Activated",
     "ActivationType": "OTASP",
     "AllowRoaming": true,
     "AutoConnect": true,
+    "Carrier": "cellular_provider",
     "HomeProvider": {
       "country": "us",
       "name": "cellular_provider"
     },
     "RoamingState": "Home",
     "ServingOperator": {
       "Code": "test-code",
       "Country": "test-country",
       "Name": "test-name"
     },
+    "SupportedCarriers": [
+      "cellular_provider",
+      "generic_provider"
+    ],
     "APN": {
       "AccessPointName": "test-apn",
       "Name": "test-apn-name",
       "Username": "test-username",
       "Password": "test-password"
     },
     "APNList": [ {
         "AccessPointName": "test-apn0",
         "Password": "test-password0",
         "Username": "test-username0"
       }, {
         "AccessPointName": "test-apn1",
         "Password": "test-password1",
         "Username": "test-username1"
       }, {
         "AccessPointName": "test-apn2",
         "Password": "test-password2",
         "Username": "test-username2"
       }, {
         "AccessPointName": "test-apn3",
         "Password": "test-password3",
         "Username": "test-username3"
       }
-    ],
+    ],  
     "SIMLockStatus": {
       "LockType": "sim-pin",
       "LockEnabled": true
     }
   },
   "Source":"Device"
 }