In the new behavior Angular cleanups `popstate` and `hashchange` event listeners
when the root view gets destroyed, thus event handlers are not added twice
when the application is bootstrapped again.
BREAKING CHANGE:
Methods of the `PlatformLocation` class, namely `onPopState` and `onHashChange`,
used to return `void`. Now those methods return functions that can be called
to remove event handlers.
PR Close#31546
PR Close#40867
Moves the public api .d.ts files from tools/public_api_guard to
goldens/public-api.
Additionally, provides a README in the goldens directory and a script
assist in testing the current state of the repo against the goldens as
well as a command for accepting all changes to the goldens in a single
command.
PR Close#35768
