Fix: Accept phone number in public contact api (#4580)

This PR makes it possible to pass a phone number to the public contacts API.

Fixes #4023

app/controllers/public/api/v1/inboxes/contacts_controller.rb

@@ -43,6 +43,6 @@ class Public::Api::V1::Inboxes::ContactsController < Public::Api::V1::InboxesCon
   end
 
   def permitted_params
-    params.permit(:identifier, :identifier_hash, :email, :name, :avatar_url, custom_attributes: {})
+    params.permit(:identifier, :identifier_hash, :email, :name, :avatar_url, :phone_number, custom_attributes: {})
   end
 end

app/views/public/api/v1/models/_contact.json.jbuilder

@@ -1,3 +1,4 @@
 json.id resource.id
 json.name resource.name
 json.email resource.email
+json.phone_number resource.phone_number