Update Angular embedding sample (#2147)

- Replace `package:js` usage with `dart:js_interop`
- Remove and ignore `package-lock.json` since it keeps causing security
warnings: https://github.com/flutter/samples/security/dependabot. It's
not necessary for this sample and the constraints already present in the
`package.json`.
- Update to Angular 17.1

web_embedding/ng-flutter/.gitignore

@@ -7,6 +7,7 @@
 /bazel-out
 
 # Node
+package-lock.json
 /node_modules
 npm-debug.log
 yarn-error.log