The app should never know the user declined usage of an API. When any app uses a privacy reducing API, the user should be able to know when that occurs. Microphone, location, etc, should be a small overlay like maybe the battery indicator icon where they can know when the app would have violated their privacy.
Yeah but the first time, the user has to decide whether he wants to allow or disallow. It's system dialog, the app can't interfere with it in any way. The icon you want is then shown in the notification area.