增加按键震动功能

1，可以在InputReader.cpp中来处理，在KeyboardInputMapper类的process中来处理获取的按键，然后再调用vibrator接口。
2，参照virtual key的处理方式，可以根据Setting中的feedback使能来判断是否需要震动；文件PhoneWindowManager.java
中有接口interceptKeyBeforeDispatching，这个接口中可以根据需要来处理。
例如：
if (keyCode == KeyEvent.KEYCODE_HOME) {
            // If a system window has focus, then it doesn't make sense
            // right now to interact with applications.
            WindowManager.LayoutParams attrs = win != null ? win.getAttrs() : null;
           Intent service = new Intent();
         service.setClassName(mContext, "com.android.settings.SoundSettings");
         ContentResolver res = mContext.getContentResolver();
   if(1 == Settings.System.getInt(res, Settings.System.HAPTIC_FEEDBACK_ENABLED,0))//when setting feedback enable
   {
    performHapticFeedbackLw(null, HapticFeedbackConstants.KEYBOARD_TAP, true); //启动震动
   }
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