ad accounts-{ad account id}-product group promotions

Number of APIs: 3

1. Create product group promotions POST {{baseUrl}}/ad_accounts/:ad_account_id/product_group_promotions

2. Get a product group promotion by id GET {{baseUrl}}/ad_accounts/:ad_account_id/product_group_promotions/:product_group_promotion_id

3. Update product group promotions PATCH {{baseUrl}}/ad_accounts/:ad_account_id/product_group_promotions