message: fix(deps): require google-gax 2.7.0
diff: "extend": "^3.0.2",
  "gcp-metadata": "^3.5.0",
  "google-auth-library": "^5.10.1",
  - "google-gax": "^2.1.0",
  + "google-gax": "^2.7.0",
  "is": "^3.3.0",
  "on-finished": "^2.3.0",
  "pumpify": "^2.0.1",
  