* The problem was with the `fireChildActivationStart` function. It was taking a `path` param, which was an
array of `ActivatedRouteSnapshot`s. The function was being fired for each piece of the route that was being
activated. This resulted in far too many `ChildActivationStart` events being fired, and being fired on routes
that weren't actually getting activated. This change fires the event only for those routes that are actually
being activated.
fixes#18942
PR Close#19043
BREAKING CHANGE: the values `true`, `false`, `legacy_enabled` and `legacy_disabled` for the router parameter `initialNavigation` have been removed as they were deprecated. Use `enabled` or `disabled` instead.
PR Close#18781
Jason Aden
Miško Hevery
Olivier Combe
Jason Aden
Tobias Bosch