Get the trend of ETCD DB size

GET /v1/monitoring-etcd/metric/db-size/result/transition?clusterIds=text&start=text&end=text HTTP/1.1
Accept: */*

[
  {
    "metrics": {
      "cluster": "thingcluster",
      "node": "apps-gpu-v100"
    },
    "samples": [
      136192000,
      136192000,
      136192000
    ],
    "timestamps": [
      136192000,
      136192000,
      136192000
    ],
    "values": null
  }
]