The webrtc busy state could be idle, but system dialer connected

src/org/thoughtcrime/securesms/service/WebRtcCallService.java

@@ -602,6 +602,7 @@ public class WebRtcCallService extends Service implements InjectableType, PeerCo
       switch (callState) {
         case STATE_DIALING:
         case STATE_REMOTE_RINGING: setCallInProgressNotification(TYPE_OUTGOING_RINGING, this.recipient);    break;
+        case STATE_IDLE:
         case STATE_ANSWERING:      setCallInProgressNotification(TYPE_INCOMING_CONNECTING, this.recipient); break;
         case STATE_LOCAL_RINGING:  setCallInProgressNotification(TYPE_INCOMING_RINGING, this.recipient);    break;
         case STATE_CONNECTED:      setCallInProgressNotification(TYPE_ESTABLISHED, this.recipient);         break;
@@ -609,6 +610,10 @@ public class WebRtcCallService extends Service implements InjectableType, PeerCo
       }
     }
 
+    if (callState == CallState.STATE_IDLE) {
+      stopForeground(true);
+    }
+
     sendMessage(recipient, SignalServiceCallMessage.forBusy(new BusyMessage(callId)));
     insertMissedCall(getRemoteRecipient(intent), false);
   }