Disable use of twilight mode for auto-brightness.

This adjustment is still experimental.

Bug: 7165399
Change-Id: I3fcf361933995d02a5329eeaec80155b39371ba3

Author: Jeff Brown

core/java/android/os/PowerManager.java

@@ -339,6 +339,15 @@ public static boolean useScreenAutoBrightnessAdjustmentFeature() {
         return SystemProperties.getBoolean("persist.power.useautobrightadj", false);
     }
 
+    /**
+     * Returns true if the twilight service should be used to adjust screen brightness
+     * policy.  This setting is experimental and disabled by default.
+     * @hide
+     */
+    public static boolean useTwilightAdjustmentFeature() {
+        return SystemProperties.getBoolean("persist.power.usetwilightadj", false);
+    }
+
     /**
      * Creates a new wake lock with the specified level and flags.
      * <p>

services/java/com/android/server/power/DisplayPowerController.java

@@ -44,7 +44,6 @@
 import android.view.Display;
 
 import java.io.PrintWriter;
-import java.io.StringWriter;
 import java.util.concurrent.Executor;
 
 /**
@@ -95,7 +94,8 @@ final class DisplayPowerController {
     // when it is especially dark outside.  The light sensor tends to perform
     // poorly at low light levels so we compensate for it by making an
     // assumption about the environment.
-    private static final boolean USE_TWILIGHT_ADJUSTMENT = true;
+    private static final boolean USE_TWILIGHT_ADJUSTMENT =
+            PowerManager.useTwilightAdjustmentFeature();
 
     // Specifies the maximum magnitude of the time of day adjustment.
     private static final float TWILIGHT_ADJUSTMENT_MAX_GAMMA = 1.5f;