title: TelephonyManager's PhoneStateListener is not called on Nougat
body: <p>I have made a sample app and the PhoneStateListener</p>
  
  <pre><code>TelephonyManager telephony = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE); //TelephonyManager object
      telephony.listen(new PhoneStateListener() {
          @Override
          public void onCallStateChanged(int state, String incomingNumber) {
              Log.i("brian", "call state = " + state + " incoming number " + incomingNumber);
              switch (state) {
                  case TelephonyManager.CALL_STATE_IDLE:
                      break;
                  case TelephonyManager.CALL_STATE_RINGING:
  
                      break;
                  case TelephonyManager.CALL_STATE_OFFHOOK:
  
                      break;
              }
          }
      }, PhoneStateListener.LISTEN_CALL_STATE); //Register our listener with TelephonyManager
  
      Log.i("brian", "READ_PHONE_STATE = " + ContextCompat.checkSelfPermission(this,
              Manifest.permission.READ_PHONE_STATE));
  </code></pre>
  
  <p>Works as expected, but when I add the above code to my much larger application the onCallStateChanged is only called when it is subscribed initially. No phone state changes are notified to me. On both projects the bottom log line "READ_PHONE_STATE = " was always granted and I'm targeting sdk 22 so no runtime permissions I think. In my larger app I have the code pasted in both the main activity and a long standing service, neither get state change events. They both work when I run my code on an android &lt; 7.0 and I have no idea why. Don't see anything substantial in the warning or error logs.</p>