fix(deps): update dependency google-gax to ^0.24.0 (#369)

Author: renovate[bot]

package.json

@@ -59,7 +59,7 @@
     "extend": "^3.0.2",
     "gcp-metadata": "^0.9.0",
     "google-auth-library": "^3.0.0",
-    "google-gax": "^0.23.0",
+    "google-gax": "^0.24.0",
     "is": "^3.2.1",
     "lodash.merge": "^4.6.1",
     "on-finished": "^2.3.0",