Add KEYCODE_PAIRING.

Used for initiating a peripheral pairing mode.

Change-Id: I7e8439d27491ccc72d045cabf5751a35b9113aa7
diff --git a/include/input/InputEventLabels.h b/include/input/InputEventLabels.h
index c6eef9b..36be4fc 100644
--- a/include/input/InputEventLabels.h
+++ b/include/input/InputEventLabels.h
@@ -264,6 +264,7 @@
     DEFINE_KEYCODE(MEDIA_AUDIO_TRACK),
     DEFINE_KEYCODE(SLEEP),
     DEFINE_KEYCODE(WAKEUP),
+    DEFINE_KEYCODE(PAIRING),
 
     { NULL, 0 }
 };