chore(tsickle): add @Annotation annotations

This lets users continue using runtime-sideeffect Decorators if they choose,
only down-leveling the marked ones to Annotations.

Also remove the "skipTemplateCodegen" option, which is no longer needed
since Angular compiles with tsc-wrapped rather than ngc. The former doesn't
include any codegen.

modules/@angular/router-deprecated/src/lifecycle/lifecycle_annotations.ts

@@ -36,6 +36,7 @@ export {routerCanDeactivate, routerCanReuse, routerOnActivate, routerOnDeactivat
  * ### Example
  *
  * {@example router/ts/can_activate/can_activate_example.ts region='canActivate' }
+ * @Annotation
  */
 export var CanActivate:
     (hook: (next: ComponentInstruction, prev: ComponentInstruction) => Promise<boolean>| boolean) =>

modules/@angular/router-deprecated/src/route_config/route_config_decorator.ts

@@ -10,6 +10,7 @@ export {AsyncRoute, AuxRoute, Redirect, Route, RouteDefinition} from './route_co
  * The `RouteConfig` decorator defines routes for a given component.
  *
  * It takes an array of {@link RouteDefinition}s.
+ * @Annotation
  */
 export var RouteConfig: (configs: RouteDefinition[]) => ClassDecorator =
     makeDecorator(RouteConfigAnnotation);