Update react monorepo to v16.9.0

Author: renovate-bot

src/React.Core/package-lock.json

@@ -9,8 +9,8 @@
     "@babel/core": "7.4.5",
     "@babel/standalone": "7.4.5",
     "prop-types": "15.7.2",
-    "react": "16.8.6",
-    "react-dom": "16.8.6",
+    "react": "16.9.0",
+    "react-dom": "16.9.0",
     "webpack": "4.35.3",
     "webpack-cli": "3.3.9"
   }