Add comment warning to not use hardware based autobrightness support.

This is deprecated and will be removed in the next release.

Change-Id: I23c5e711fd8e6768da2f5190d1b6c9fa77de41a6
Signed-off-by: Mike Lockwood <lockwood@android.com>
diff --git a/core/res/res/values/config.xml b/core/res/res/values/config.xml
index 274ec2b..057e10a 100644
--- a/core/res/res/values/config.xml
+++ b/core/res/res/values/config.xml
@@ -71,7 +71,9 @@
          the slider can be opened (for example, in a pocket or purse). -->
     <bool name="config_bypass_keyguard_if_slider_open">true</bool>
     
-    <!-- Flag indicating whether the device supports automatic brightness mode in hardware. -->
+    <!-- Flag indicating whether the device supports automatic brightness mode in hardware.
+         WARNING - DO NOT USE THIS FEATURE
+         Hardware auto brightness support is deprecated and will be removed in the next release. -->
     <bool name="config_hardware_automatic_brightness_available">false</bool>
 
     <!-- Flag indicating whether the we should enable the automatic brightness in Settings.