PROMO-1296 Added exclude_characters field for bulk coupon api /v3/promotions/{promotion id}/codegen

Author: bc-anshumishra

reference/promotions.v3.yml

@@ -338,6 +338,12 @@ paths:
                   description: 'An optional single character (_ or -) that will be placed between the prefix and the randomly generated code, and again between the randomly generated code and the suffix. It will only be applied if a valid prefix or suffix is present.'
                   example: _
                   maxLength: 1
+                exclude_characters:
+                  pattern: '[A-Z0-9]'
+                  type: array
+                  description: 'An optional array of single length string elements to exclude from the generated coupon codes. Only capital letters and numbers are allowed. The default value is an empty array [].'
+                  example: ["1", "2", "3", "4", "5", "A", "B", "C", "D", "E"]
+                  maxLength: 26
                 code_length:
                   type: integer
                   description: 'The length of the random string to be generated for each coupon code. The value must be between 6 and 16. The default length is 16. The total length of each generated coupon code is calculated as: `code_length` + length of `prefix` + length of `suffix`. The maximum total length of a coupon code is 50.'