chore: Use "create!" and "save!" bang methods when not checking the result (#5358)

* Use "create!" when not checking for errors on the result
* Use "save!" when not checking the result

app/controllers/api/v1/widget/conversations_controller.rb

@@ -9,7 +9,7 @@ class Api::V1::Widget::ConversationsController < Api::V1::Widget::BaseController
     ActiveRecord::Base.transaction do
       process_update_contact
       @conversation = create_conversation
-      conversation.messages.create(message_params)
+      conversation.messages.create!(message_params)
     end
   end
 
@@ -59,7 +59,7 @@ class Api::V1::Widget::ConversationsController < Api::V1::Widget::BaseController
 
     unless conversation.resolved?
       conversation.status = :resolved
-      conversation.save
+      conversation.save!
     end
     head :ok
   end