fix: Twilio channel selection when MessagingServiceSid is empty (#5040)

- Fixes channel selection logic in incoming_message_service for Twilio messages

ref: #4242

app/services/twilio/incoming_message_service.rb

@@ -4,6 +4,8 @@ class Twilio::IncomingMessageService
   pattr_initialize [:params!]
 
   def perform
+    return if twilio_channel.blank?
+
     set_contact
     set_conversation
     @message = @conversation.messages.create(
@@ -19,14 +21,17 @@ class Twilio::IncomingMessageService
 
   private
 
-  def twilio_inbox
-    @twilio_inbox ||=
-      ::Channel::TwilioSms.find_by(messaging_service_sid: params[:MessagingServiceSid]) ||
-      ::Channel::TwilioSms.find_by!(account_sid: params[:AccountSid], phone_number: params[:To])
+  def twilio_channel
+    @twilio_channel ||= ::Channel::TwilioSms.find_by(messaging_service_sid: params[:MessagingServiceSid]) if params[:MessagingServiceSid].present?
+    if params[:AccountSid].present? && params[:To].present?
+      @twilio_channel ||= ::Channel::TwilioSms.find_by!(account_sid: params[:AccountSid],
+                                                        phone_number: params[:To])
+    end
+    @twilio_channel
   end
 
   def inbox
-    @inbox ||= twilio_inbox.inbox
+    @inbox ||= twilio_channel.inbox
   end
 
   def account
@@ -34,7 +39,7 @@ class Twilio::IncomingMessageService
   end
 
   def phone_number
-    twilio_inbox.sms? ? params[:From] : params[:From].gsub('whatsapp:', '')
+    twilio_channel.sms? ? params[:From] : params[:From].gsub('whatsapp:', '')
   end
 
   def formatted_phone_number
@@ -78,7 +83,7 @@ class Twilio::IncomingMessageService
   end
 
   def additional_attributes
-    if twilio_inbox.sms?
+    if twilio_channel.sms?
       {
         from_zip_code: params[:FromZip],
         from_country: params[:FromCountry],