Android/JAVA - 액티비티를 항상 최상위에 띄우기

getWindow().addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED

                        | WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD

                        | WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON

                        | WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);