Call Device.SetCarrier when the ONC Carrier property is specified.

components/onc/onc_constants.cc

Index: components/onc/onc_constants.cc
diff --git a/components/onc/onc_constants.cc b/components/onc/onc_constants.cc
index 8945059aa24f46bd0fbab201e2acc340657195c9..2d770854216ae738d47698b5ac97499d73498838 100644
--- a/components/onc/onc_constants.cc
+++ b/components/onc/onc_constants.cc
@@ -90,6 +90,7 @@ namespace cellular {
 const char kActivationState[] = "ActivationState";
 const char kActivated[] = "Activated";
 const char kActivating[] = "Activating";
+const char kAutoConnect[] = "AutoConnect";
 const char kNotActivated[] = "NotActivated";
 const char kPartiallyActivated[] = "PartiallyActivated";
 const char kActivationType[] = "ActivationType";