待机界面-点击亮度调节快捷键，在LCD亮度渐变时有闪屏现象

解决方法：

    路径：frameworks/base/services/java/com/android/server/power/RampAnimator.java

    代码：

final class RampAnimator<T> {
     public boolean animateTo(int target, int rate) {
         // Immediately jump to the target the first time.
         if (mFirstTime) {
-            mFirstTime = false;
+            //mFirstTime = false;
             mProperty.setValue(mObject, target);