fix: only send call reject event when needed

This is fixes rejects by missed calls, which should only reject a new call locally and not send a event if they are already in a call

lib/src/voip/README.md

@@ -133,6 +133,8 @@ newCall.answer();
 newCall.reject();
 ```
 
+To reject a call locally but not send a event, use `newCall.reject(shouldEmit: false)`
+
 ### 5.Render media stream
 
 The basic process of rendering a video stream is as follow code.

lib/src/voip/call.dart

@@ -1022,8 +1022,10 @@ class CallSession {
     }
     Logs().d('[VOIP] Rejecting call: $callId');
     await terminate(CallParty.kLocal, CallErrorCode.UserHangup, shouldEmit);
-    await sendCallReject(
-        room, callId, Timeouts.lifetimeMs, localPartyId, reason);
+    if (shouldEmit) {
+      await sendCallReject(
+          room, callId, Timeouts.lifetimeMs, localPartyId, reason);
+    }
   }
 
   Future<void> hangup([String? reason, bool suppressEvent = false]) async {

lib/src/voip/voip.dart

@@ -224,8 +224,8 @@ class VoIP {
     if (!delegate.canHandleNewCall &&
         (confId == null || confId != currentGroupCID)) {
       Logs().v(
-          '[glare] [VOIP] onCallInvite: Unable to handle new calls, maybe user is busy.');
-      await newCall.reject(reason: 'busy', shouldEmit: false);
+          '[VOIP] onCallInvite: Unable to handle new calls, maybe user is busy.');
+      await newCall.reject(reason: CallErrorCode.UserBusy, shouldEmit: false);
       delegate.handleMissedCall(newCall);
       return;
     }