[binary_sensor] Fix reporting of 'unknown' (#12296)

Co-authored-by: Jonathan Swoboda <154711427+swoboda1337@users.noreply.github.com>
Co-authored-by: J. Nick Koston <nick@home-assistant.io>

esphome/components/binary_sensor/binary_sensor.cpp

@@ -34,13 +34,20 @@ void BinarySensor::publish_initial_state(bool new_state) {
 void BinarySensor::send_state_internal(bool new_state) {
   // copy the new state to the visible property for backwards compatibility, before any callbacks
   this->state = new_state;
-  // Note that set_state_ de-dups and will only trigger callbacks if the state has actually changed
-  if (this->set_state_(new_state)) {
-    ESP_LOGD(TAG, "'%s': New state is %s", this->get_name().c_str(), ONOFF(new_state));
+  // Note that set_new_state_ de-dups and will only trigger callbacks if the state has actually changed
+  this->set_new_state(new_state);
+}
+
+bool BinarySensor::set_new_state(const optional<bool> &new_state) {
+  if (StatefulEntityBase::set_new_state(new_state)) {
+    // weirdly, this file could be compiled even without USE_BINARY_SENSOR defined
 #if defined(USE_BINARY_SENSOR) && defined(USE_CONTROLLER_REGISTRY)
     ControllerRegistry::notify_binary_sensor_update(this);
 #endif
+    ESP_LOGD(TAG, "'%s': %s", this->get_name().c_str(), ONOFFMAYBE(new_state));
+    return true;
   }
+  return false;
 }
 
 void BinarySensor::add_filter(Filter *filter) {