Rc switch library display received values only one times using serial monitor
You can save the previous received value, and only print if it is different from what you just received.
Something like this:
// near the top
const int rightLED = 4;
const int leftLED = 7;
const unsigned long goRight = 5592323;
const unsigned long goLeft = 5592332;

// to hold the state
unsigned long previousValue = 0;

// ...

// loop code
void loop()
{
  if (receiver.available())
  {
    unsigned long receivedValue = receiver.getReceivedValue();
    if (receivedValue != previousValue) {
      // something changed
      if (receivedValue == goRight)
      {
        moveRight();
      }
      if (receivedValue == goLeft)
      {
        moveLeft();
      }
      // remember the current value
      previousValue = receivedValue;
    }
    receiver.resetAvailable();
  }
}