PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/angular/angular/blob/main/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• angular.dev application / infrastructure changes
• Other... Please describe:

What is the current behavior?

This PR fixes the issue described here: #58493 (comment)

Currently, APP_INITIALIZER providers are transformed into:

provideAppInitializer((service: Service) => {
  return () => service.init();
})(inject(Service)));

What is the new behavior?

provideAppInitializer(() => {
  const initializerFn = ((service: Service) => {
    return () => service.init();
  })(inject(Service));
  return initializerFn();
});

Does this PR introduce a breaking change?

• Yes
• No

Other information

This PR also adds support to the useFactory() {} method shorthand.
Let me know if you want me to separate this into a distinct PR.