frameworks\base\services\core\java\com\android\server\policy\PhoneWindowManager.java
 @Override
 public void screenTurnedOn() {
  synchronized (mLock) {
   if (mKeyguardDelegate != null) {
    mKeyguardDelegate.onScreenTurnedOn();
   }
   //add start
    if (SystemProperties.getInt("persist.sys.screen_first_on", 1) == 0) {
    android.util.Log.d("chch", "turnOffFlashLightIfNeed");
    turnOffFlashLightIfNeed();
   }else{
    SystemProperties.set("persist.sys.screen_first_on", "0");
   }
   //end
  }
 }
  //chch add start
 private void turnOffFlashLightIfNeed(){
  try{
   mCameraManager = (CameraManager) mContext.getSystemService(Context.CAMERA_SERVICE);
   mCameraId = mCameraManager.getCameraIdList()[0];
   mCameraManager.setTorchMode(mCameraId,false);
  }catch(Exception e){
   android.util.Log.d("chch", "camera error");
  }
 }
 //chch end

import android.hardware.camera2.CameraManager;

CameraManager mCameraManager; 
String mCameraId;