Add keycodes for brightness up/down

Change-Id: I8ed56b510c46f372df0fc71e1735c72058efc677
diff --git a/include/android/keycodes.h b/include/android/keycodes.h
index 282e729..cf38d1a 100644
--- a/include/android/keycodes.h
+++ b/include/android/keycodes.h
@@ -263,6 +263,8 @@
     AKEYCODE_RO              = 217,
     AKEYCODE_KANA            = 218,
     AKEYCODE_ASSIST          = 219,
+    AKEYCODE_BRIGHTNESS_DOWN = 220,
+    AKEYCODE_BRIGHTNESS_UP   = 221,
 
     // NOTE: If you add a new keycode here you must also add it to several other files.
     //       Refer to frameworks/base/core/java/android/view/KeyEvent.java for the full list.