fix(deps): update dependency google-gax to ^0.23.0 (#518)

Author: renovate[bot]

package.json

@@ -51,7 +51,7 @@
     "deep-equal": "^1.0.1",
     "extend": "^3.0.1",
     "functional-red-black-tree": "^1.0.1",
-    "google-gax": "^0.22.0",
+    "google-gax": "^0.23.0",
     "is": "^3.2.1",
     "lodash.merge": "^4.6.1",
     "protobufjs": "^6.8.6",