feat: tree-shakeable providers API updates (#22655)

Rename @Injectable({scope -> providedIn}).

Instead of {providedIn: APP_ROOT_SCOPE}, accept {providedIn: 'root'}.
Also, {providedIn: null} implies the injectable should not be added
to any scope.

PR Close #22655

packages/compiler-cli/integrationtest/bazel/injectable_def/app/src/dep.ts

@@ -35,7 +35,7 @@ export class AppComponent {
 export class DepAppModule {
 }
 
-@Injectable({scope: DepAppModule})
+@Injectable({providedIn: DepAppModule})
 export class ShakeableService {
   constructor(readonly normal: NormalService) {}
 }