title: Wake up android phone with certain words like Hi Galaxy or Ok Google
body: <p>I would like to wake up an android phone by saying for example "Hello George", but could not find any useful answers. 
  First of all , is android app needs to listen as service in background for this feature or not?
  I would appreciate if anyone knows how to implement this issue or have any clue.</p>
  
  <p>Best Regards
  Thank you</p>