fix(deps): update dependency google-gax to ^0.22.0 (#248)

Author: renovate[bot]

handwritten/datastore/package.json

@@ -51,7 +51,7 @@
     "concat-stream": "^1.6.2",
     "extend": "^3.0.1",
     "google-auth-library": "^2.0.0",
-    "google-gax": "^0.20.0",
+    "google-gax": "^0.22.0",
     "is": "^3.2.1",
     "lodash.merge": "^4.6.1",
     "split-array-stream": "^2.0.0",