Revert "fix(router): do not finish bootstrap until all the routes are resolved (#14608)"

This reverts commit 2a191cae2d.

tools/public_api_guard/common/index.d.ts

@@ -86,9 +86,6 @@ export declare class Location {
     static stripTrailingSlash(url: string): string;
 }
 
-/** @experimental */
-export declare const LOCATION_INITIALIZED: InjectionToken<Promise<any>>;
-
 /** @experimental */
 export interface LocationChangeEvent {
     type: string;