openapiv2: Field options are not properly rendered for repeated fields

I need to generate swagger json using proto annotations. generated schema should look like this

"schema": {
              "type": "object",
              "example": {
                "product_id": ["8900099100000113079", "8900099100000082373"]
              },
              "properties": {
                "product_id": {
                  "type": "array",
                  "items": {
                    "type": "string",
                    "maxLength": 19,
                   "minLength": 1,
                   "pattern": "^[0-9]+$"
                  },
                  "description": "Only digits are allowed.",
                  "title": "Provide list of ids"           
                }
              }
            }

and the annotation added was something like this

message product { 
repeated string product_id=1[(grpc.gateway.protoc_gen_openapiv2.options.openapiv2_field) = {
                  pattern: "^[0-9]+$"
                  max_length: 19
                  min_length: 1
                  description: "Only digits are allowed."
    }];
}

But the problem is above annotation is generating schema like this

"schema": {
              "type": "object",
              "example": {
                "product_id": ["8900099100000113079", "8900099100000082373"]
              },
              "properties": {
                "product_id": {
                  "type": "array",
                  "items": {
                    "type": "string"                   
                  },
                  "description": "Only digits are allowed.",
                  "title": "Provide list of ids",
                   "maxLength": 19,
                   "minLength": 1,
                   "pattern": "^[0-9]+$"           
                }
              }
            }

which is not correct. We could not find the relevant example in a_bit_of_everything.proto.

Please help in adding the annotations.