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/common/http/src/request.ts

@@ -88,7 +88,8 @@ export class HttpRequest<T> {
   /**
    * Outgoing headers for this request.
    */
-  readonly headers: HttpHeaders;
+  // TODO(issue/24571): remove '!'.
+  readonly headers !: HttpHeaders;
 
   /**
    * Whether this request should be made in a way that exposes progress events.
@@ -119,7 +120,8 @@ export class HttpRequest<T> {
   /**
    * Outgoing URL parameters.
    */
-  readonly params: HttpParams;
+  // TODO(issue/24571): remove '!'.
+  readonly params !: HttpParams;
 
   /**
    * The outgoing URL with all URL parameters set.