build(bazel): Turning on strictPropertyInitialization for Angular. (#24572)

All errors for existing fields have been detected and suppressed with a
`!` assertion.

Issue/24571 is tracking proper clean up of those instances.

One-line change required in ivy/compilation.ts, because it appears that
the new syntax causes tsickle emitted node to no longer track their
original sourceFiles.

PR Close #24572

packages/router/src/router_state.ts

@@ -106,15 +106,19 @@ export function createEmptyStateSnapshot(
  */
 export class ActivatedRoute {
   /** The current snapshot of this route */
-  snapshot: ActivatedRouteSnapshot;
+  // TODO(issue/24571): remove '!'.
+  snapshot !: ActivatedRouteSnapshot;
   /** @internal */
   _futureSnapshot: ActivatedRouteSnapshot;
   /** @internal */
-  _routerState: RouterState;
+  // TODO(issue/24571): remove '!'.
+  _routerState !: RouterState;
   /** @internal */
-  _paramMap: Observable<ParamMap>;
+  // TODO(issue/24571): remove '!'.
+  _paramMap !: Observable<ParamMap>;
   /** @internal */
-  _queryParamMap: Observable<ParamMap>;
+  // TODO(issue/24571): remove '!'.
+  _queryParamMap !: Observable<ParamMap>;
 
   /** @internal */
   constructor(
@@ -257,13 +261,17 @@ export class ActivatedRouteSnapshot {
   /** @internal */
   _resolve: ResolveData;
   /** @internal */
-  _resolvedData: Data;
+  // TODO(issue/24571): remove '!'.
+  _resolvedData !: Data;
   /** @internal */
-  _routerState: RouterStateSnapshot;
+  // TODO(issue/24571): remove '!'.
+  _routerState !: RouterStateSnapshot;
   /** @internal */
-  _paramMap: ParamMap;
+  // TODO(issue/24571): remove '!'.
+  _paramMap !: ParamMap;
   /** @internal */
-  _queryParamMap: ParamMap;
+  // TODO(issue/24571): remove '!'.
+  _queryParamMap !: ParamMap;
 
   /** @internal */
   constructor(