Make sure to turn off led after pulse()

setLightLocked() will update mColor. This will cause the led to not be
turned off after the pulse.
When notificationManager starts a attention pulse the led will be kept
on. Since attention is of highest prio nothing can turn it off.
This is fixed by resetting mColor back to 0 after the call.

Change-Id: Id60ef96e5c21b47c23002f0bcf2fae7fb3f2ca10

services/java/com/android/server/LightsService.java

@@ -96,6 +96,7 @@ public class LightsService {
             synchronized (this) {
                 if (mColor == 0 && !mFlashing) {
                     setLightLocked(color, LIGHT_FLASH_HARDWARE, onMS, 1000, BRIGHTNESS_MODE_USER);
+                    mColor = 0;
                     mH.sendMessageDelayed(Message.obtain(mH, 1, this), onMS);
                 }
             }