fix: Ensure messages go to correct conversation when receive multi user in 1 LINE webhook (#12322)

# Pull Request Template

## Description
Ensure messages go to correct conversation when receive multi user in 1
LINE webhook.
base on
[document](https://developers.line.biz/en/reference/messaging-api/#webhook-event-objects:~:text=There%20is%20not%20necessarily%20one%20user%20per%20webhook).
it said
```
There is not necessarily one user per webhook. 
A message event from person A and a follow event from person B may be in the same webhook.
```

this PR has 1 break changes.
In old version. when receive
[follow](https://developers.line.biz/en/reference/messaging-api/#follow-event)
event, it will create conversation with no messages.
After this PR. when receive follow event, it will not create
conversation, contact and messages

## Type of change

Please delete options that are not relevant.

- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [x] Breaking change (fix or feature that would cause existing
functionality not to work as expected)
- [ ] This change requires a documentation update

## How Has This Been Tested?
add test case.
and follow event test by delete conversation, and block and unblock line
account

## Checklist:

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my code
- [ ] I have commented on my code, particularly in hard-to-understand
areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream
modules

---------

Co-authored-by: mix5003 <mix5003@debian.debian>
Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

app/services/line/incoming_message_service.rb

@@ -10,11 +10,6 @@ class Line::IncomingMessageService
     # probably test events
     return if params[:events].blank?
 
-    line_contact_info
-    return if line_contact_info['userId'].blank?
-
-    set_contact
-    set_conversation
     parse_events
   end
 
@@ -22,6 +17,14 @@ class Line::IncomingMessageService
 
   def parse_events
     params[:events].each do |event|
+      next unless event_type_message?(event)
+
+      get_line_contact_info(event)
+      next if @line_contact_info['userId'].blank?
+
+      set_contact
+      set_conversation
+
       next unless message_created? event
 
       attach_files event['message']
@@ -30,8 +33,6 @@ class Line::IncomingMessageService
   end
 
   def message_created?(event)
-    return unless event_type_message?(event)
-
     @message = @conversation.messages.build(
       content: message_content(event),
       account_id: @inbox.account_id,
@@ -119,13 +120,13 @@ class Line::IncomingMessageService
     @account ||= inbox.account
   end
 
-  def line_contact_info
-    @line_contact_info ||= JSON.parse(inbox.channel.client.get_profile(params[:events].first['source']['userId']).body)
+  def get_line_contact_info(event)
+    @line_contact_info = JSON.parse(inbox.channel.client.get_profile(event['source']['userId']).body)
   end
 
   def set_contact
     contact_inbox = ::ContactInboxWithContactBuilder.new(
-      source_id: line_contact_info['userId'],
+      source_id: @line_contact_info['userId'],
       inbox: inbox,
       contact_attributes: contact_attributes
     ).perform
@@ -152,15 +153,15 @@ class Line::IncomingMessageService
 
   def contact_attributes
     {
-      name: line_contact_info['displayName'],
-      avatar_url: line_contact_info['pictureUrl'],
+      name: @line_contact_info['displayName'],
+      avatar_url: @line_contact_info['pictureUrl'],
       additional_attributes: additional_attributes
     }
   end
 
   def additional_attributes
     {
-      social_line_user_id: line_contact_info['userId']
+      social_line_user_id: @line_contact_info['userId']
     }
   end