refactor(nodejs): move build cop to flakybot (#26)

This PR was generated using Autosynth. 🌈 Synth log will be available here: https://source.cloud.google.com/results/invocations/1bcecc39-aa5c-40f4-9453-955704c7ca01/targets - [ ] To automatically regenerate this PR, check this box. Source-Link: googleapis/synthtool@57c23fa

Author: yoshi-automation

.kokoro/samples-test.sh

@@ -4,7 +4,7 @@
  "git": {
  "name": ".",
  "remote": "https://github.com/googleapis/nodejs-video-transcoder.git",
- "sha": "c4062fda1fb19ac3dccdfd2b8ca76dee23bb7891"
+ "sha": "139b47af2245bf64ad57e60daedd7fa44dba58d3"
  }
  },
  {
@@ -19,7 +19,7 @@
  "git": {
  "name": "synthtool",
  "remote": "https://github.com/googleapis/synthtool.git",
- "sha": "363fe305e9ce34a6cd53951c6ee5f997094b54ee"
+ "sha": "57c23fa5705499a4181095ced81f0ee0933b64f6"
  }
  }
  ],