fix: add dependency to fix tests (#1658)

* fix: add overrides to fix #1657

* fix: remove overrides, install pdfmake directly

Author: leahecole

gax/package.json

@@ -51,6 +51,7 @@
     "mocha": "^9.0.0",
     "ncp": "^2.0.0",
     "null-loader": "^4.0.0",
+    "pdfmake": "0.2.12",
     "protobufjs-cli": "1.1.3",
     "proxyquire": "^2.0.1",
     "pumpify": "^2.0.0",
@@ -63,6 +64,7 @@
     "webpack": "^4.0.0",
     "webpack-cli": "^4.0.0"
   },
+
   "scripts": {
     "docs": "compodoc src/",
     "pretest": "npm run prepare",