Receive events as new flow in NewMessageViewModel

Co-authored-by: Fanchao Liu <273191+simophin@users.noreply.github.com>

app/src/main/java/org/thoughtcrime/securesms/conversation/newmessage/NewMessageViewModel.kt

@@ -31,7 +31,7 @@ class NewMessageViewModel @Inject constructor(
     val state = _state.asStateFlow()
 
     private val _event = Channel<Event>()
-    val event = _event.receiveAsFlow()
+    val event: Flow<Event> get() = _event.receiveAsFlow()
 
     private val _qrErrors = Channel<String>()
     val qrErrors: Flow<String> = _qrErrors.receiveAsFlow()