Change AddressableLED example to use consistent PWM port (#2168)

wpilibjExamples/src/main/java/edu/wpi/first/wpilibj/examples/addressableled/Robot.java

@@ -19,9 +19,9 @@ public class Robot extends TimedRobot {
 
   @Override
   public void robotInit() {
-    // PWM port 0
+    // PWM port 9
     // Must be a PWM header, not MXP or DIO
-    m_led = new AddressableLED(0);
+    m_led = new AddressableLED(9);
 
     // Reuse buffer
     // Default to a length of 60, start empty output