Add ResetModem method and call it once non_cellular activation is done.

chrome/browser/chromeos/cros/network_library_impl_stub.cc

Index: chrome/browser/chromeos/cros/network_library_impl_stub.cc
diff --git a/chrome/browser/chromeos/cros/network_library_impl_stub.cc b/chrome/browser/chromeos/cros/network_library_impl_stub.cc
index 476f627e4e43e9350a8a9423c0714653cc736522..94eee733756d317510acd7f6e04e6f64f5e19f13 100644
--- a/chrome/browser/chromeos/cros/network_library_impl_stub.cc
+++ b/chrome/browser/chromeos/cros/network_library_impl_stub.cc
@@ -687,6 +687,9 @@ void NetworkLibraryImplStub::SetCarrier(
       base::TimeDelta::FromMilliseconds(10000));
 }
 
+void NetworkLibraryImplStub::ResetModem() {
+}
+
 bool NetworkLibraryImplStub::IsCellularAlwaysInRoaming() {
   return false;
 }