After updating a protected branch, include it's access levels in the JSON response.

1. We might need to update/delete access levels that were created in
   this `update` call without a page refresh.

2. The JS relies on the JSON response for the IDs of the newly created
   access level records.

app/controllers/projects/protected_branches_controller.rb

@@ -34,7 +34,7 @@ class Projects::ProtectedBranchesController < Projects::ApplicationController
 
     if @protected_branch.valid?
       respond_to do |format|
-        format.json { render json: @protected_branch, status: :ok }
+        format.json { render json: @protected_branch, status: :ok, include: [:merge_access_levels, :push_access_levels] }
       end
     else
       respond_to do |format|