fix(deps): google-gax v2.17.0 with mTLS (#400)

Author: bcoe

packages/google-cloud-securitycenter/package.json

@@ -42,7 +42,7 @@
     "Security Command Center API"
   ],
   "dependencies": {
-    "google-gax": "^2.12.0"
+    "google-gax": "^2.17.0"
   },
   "devDependencies": {
     "@types/mocha": "^8.0.0",