Generate grok custom pattern to message filed

[fadjar340 (Fadjar Tandabawana)]

@Mohan_vel

    PUT _ingest/pipeline/dissectpipeline
    {
      "description" : "split message content",
      "processors": [
        {
          "grok": {
              "field": "message",
              "patterns": ["\"agentId:%{NOTSPACE:agentId}\""]
            }
        }
       }
      ]
    }

There are unnecessary bracket that make an error

     PUT _ingest/pipeline/dissectpipeline
    {
      "description" : "split message content",
      "processors": [
        {
          "grok": {
              "field": "message",
              "patterns": ["\"agentId:%{NOTSPACE:agentId}\""]
            }
        }
       }  <= unnecessary 
      ]
    }