android 5 设置图案锁，锁屏界面进入相机拍照、查看锁定的照片后，退出锁屏界面再进入相机，不能正常拍照，界面白屏。

将文件alps/frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/phone/KeyguardBottomAreaView.java内的函数launchCamera()作如下修改：
 
 if (intent == SECURE_CAMERA_INTENT && !wouldLaunchResolverActivity) {
            if (DEBUG) Log.d(TAG, "launchCamera() - launch SECURE_CAMERA_INTENT") ;
 
            mContext.startActivityAsUser(intent, UserHandle.CURRENT);
        } else {
 
修改为
 
if (intent == SECURE_CAMERA_INTENT && !wouldLaunchResolverActivity) {
            if (DEBUG) Log.d(TAG, "launchCamera() - launch SECURE_CAMERA_INTENT") ;
            ///M: [ALPS01844520] Insecure Camera may be resumed if no CLEAR_TOP attribute.
          intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TOP);//Add by mtk
            mContext.startActivityAsUser(intent, UserHandle.CURRENT);
        } else {