Keep old country ISO for country-related emergency number if signal is lost

                            TelephonyManager.EXTRA_NETWORK_COUNTRY);

                    logd("ACTION_NETWORK_COUNTRY_CHANGED: PhoneId: " + phoneId + " CountryIso: "

                            + countryIso);

                    // Sometimes the country is updated as an empty string when the network signal

                    // is lost; though we may not call emergency when there is no signal, we want

                    // to keep the old country iso to provide country-related emergency numbers,

                    // because they think they are still in that country. So we do need to update

                    // country change in this case.

                    if (TextUtils.isEmpty(countryIso)) {

                        return;

                    }

                    updateEmergencyNumberDatabaseCountryChange(countryIso);

                }

                return;