title: Android: check if brightness control is possible
body: <p>I'm working on a media player app that need to show the brightness control when is possible. However, Android doesn't seem to provide an API to check that. I could use a workaround to set brightness to an arbitrary value and read back the value and see if that changes anything. However, I don't think that is reliable and still looking to see if there is an official API does that. </p>
  
  <p>Thanks,</p>
  
  <p>EDIT1: I didn't make my question clear. I am not looking to change brightness but I'd like to know if brightness can be changed. For example, on Android STB (connected to HDTV),  brightness control is not possible so my app should not show brightness control button. </p>