Add auto-brightness mode to the list of backed-up settings

Change-Id: I4302b79691ed717d810748b239311cba198f6381
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index e3fc72d..2b6313d 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -1416,6 +1416,7 @@
             DIM_SCREEN,
             SCREEN_OFF_TIMEOUT,
             SCREEN_BRIGHTNESS,
+            SCREEN_BRIGHTNESS_MODE,
             VIBRATE_ON,
             NOTIFICATIONS_USE_RING_VOLUME,
             MODE_RINGER,