aggregation that can be bound to a query or filter not working

[ajays1991]

I have the following orders_index

class OrdersIndex < Chewy::Index
  settings analysis: {
    analyzer: {
      lower_keyword_autocomplete: {
        tokenizer: 'keyword',
        filter: ["lowercase"]
      }
    }
  }

  define_type Order.all.includes(:products) do
    field :total, type: 'float'
    field :total_items, type: 'long'
    field :products do
      field :name, analyzer: 'lower_keyword_autocomplete'
      field :description, analyzer: 'lower_keyword_autocomplete'
      field :price, type: 'float'
      field :category, value: ->(product) { product.category.name }, analyzer: 'lower_keyword_autocomplete'
    end
    agg :avg_price do
      { avg: { field: 'products.price'} }
    end
  end
end

Following this, i am trying to evaluate an aggregate to compute average of price for query.

Upon firing rake chewy:reset, i am unable to find avg_price field created in my orders index.