[BUG] Policy update wont work with min_doc_count dropped in new policy.

[ijunaid8989]

What is the bug?
https://opensearch.org/docs/latest/im-plugin/ism/api/#update-managed-index-policy
Updating the policy of managed index is not working.

How can one reproduce the bug?
Steps to reproduce the behavior:
I have added a policy for an index such as

    %{
      "policy" => %{
        "description" => "ISM Policy for rollover and deletion",
        "default_state" => "hot",
        "states" => [
          %{
            "name" => "hot",
            "actions" => [
              %{
                "rollover" => %{
                  "min_index_age" => "30d",
                  "min_doc_count" => 100_000 <----issue
                }
              }
            ],
            "transitions" => [
              %{
                "state_name" => "delete",
                "conditions" => %{
                  "min_index_age" => "30d"
                }
              }
            ]
          },
          %{
            "name" => "delete",
            "actions" => [
              %{
                "delete" => %{}
              }
            ]
          }
        ],
        "ism_template" => %{
          "index_patterns" => ["benefits_program_user-*"]
        }
      }
    }

policy is available.
Its attached to benefits_program_user-* index pattern and being shown as well when I try to get 'http://localhost:9200/_plugins/_ism/explain/benefits_program_user?show_policy=true'

Now I want to update the policy of this managed index with this

    %{
      "policy" => %{
        "description" => "ISM Policy for rollover and deletion",
        "default_state" => "hot",
        "states" => [
          %{
            "name" => "hot",
            "actions" => [
              %{
                "rollover" => %{
                  "min_index_age" => "10d"
                }
              }
            ],
            "transitions" => [
              %{
                "state_name" => "delete",
                "conditions" => %{
                  "min_index_age" => "10d"
                }
              }
            ]
          },
          %{
            "name" => "delete",
            "actions" => [
              %{
                "delete" => %{}
              }
            ]
          }
        ],
        "ism_template" => %{
          "index_patterns" => ["benefits_program_user-*"]
        }
      }
    }

So I first updated the policy.

which worked. then I made a request to change_policy endpoint POST.

it worked as expected but when I go to this page again

I still see the old policy.

When I start with min_doc_count in policy and then change the min age, it works but when old policy has min_doc_count and new has not.

then It wont get updated on index. I have waited for almost 12 hours.

What is the expected behavior?
It should update the new version of policy

What is your host/environment?

• OS: Docker
• Version Latest
• Plugins