title: Notify a service from a PhoneStateListener
body: <p>I have built an application that listen to call state changes, and I want to notify a service when the call_state became IDLE.</p>
  
  <p>All the components I have are functional, I just need to notify (not start) a service for this.</p>
  
  <p>What's the correct practice, maybe using AIDL?</p>
  
  <p>Because, in a PhoneStateListener, I can't bind to a service. Do I have to start an activity for that?</p>