Don't restore old brightness when cancelling brightness dialog in automatic mode.

Fixes a problem that could result in the backlight getting set to a bogus brightness
level if you open the dialog and cancel when in automatic mode.

Bug b/2015734

Change-Id: I302697e4ebd37afcdbfdd74ba0b1cc9be27ee40b
Signed-off-by: Mike Lockwood <lockwood@android.com>

src/com/android/settings/BrightnessPreference.java

@@ -120,10 +120,11 @@ public class BrightnessPreference extends SeekBarPreference implements
             if (mAutomaticAvailable) {
                 setMode(mOldAutomatic);
             }
-            // brightness needs to be restored after restoring ALS mode
+            if (!mAutomaticAvailable || mOldAutomatic == 0) {
                 setBrightness(mOldBrightness);
             }
         }
+    }
     
     private void setBrightness(int brightness) {
         try {