Repository: angular
Issue: ng generate @angular/core:control-flow migration removes the container reference even if it is used in component file
Labels: state: confirmed,area: migrations,core: control flow

### Which @angular/* package(s) are the source of the bug?

core

### Is this a regression?

Yes

### Description

when I run angular control flow migration, it removes the template reference from html which is being used in component.ts file too 
original code - 
```
import { NgIf } from '@angular/common';
import {
  Component,
  TemplateRef,
  ViewChild,
  ViewContainerRef,
  viewChild,
} from '@angular/core';
import { bootstrapApplication } from '@angular/platform-browser';
import 'zone.js';

@Component({
  selector: 'app-root',
  standalone: true,
  imports: [NgIf],
  template: `
    <h1>Hello from {{ name }}!</h1>
    <div *ngIf="showContent; then contentTemplate"></div>
    <ng-template #contentTemplate>
       <div>test content</div>
  </ng-template>
  `,
})
export class App {
  @ViewChild('contentTemplate') testContainer!: TemplateRef<unknown>;
  name = 'Angular';
  showContent = true;
  options: { value: string; html: any }[] = [];

  constructor(private viewContainerRef: ViewContainerRef) {}

  ngAfterViewInit(): void {
    this.viewContainerRef.createEmbeddedView(this.testContainer);
  }
}

bootstrapApplication(App);
```


after migration - 

```
import {
  Component,
  TemplateRef,
  ViewChild,
  ViewContainerRef,
  viewChild,
} from '@angular/core';
import { bootstrapApplication } from '@angular/platform-browser';
import 'zone.js';

@Component({
  selector: 'app-root',
  standalone: true,
  imports: [],
  template: `
    <h1>Hello from {{ name }}!</h1>
    @if (showContent) {
      <div>test content</div>
    }
    `,
})
export class App {
  @ViewChild('contentTemplate') testContainer!: TemplateRef<unknown>;
  name = 'Angular';
  showContent = true;
  options: { value: string; html: any }[] = [];

  constructor(private viewContainerRef: ViewContainerRef) {}

  ngAfterViewInit(): void {
    this.viewContainerRef.createEmbeddedView(this.testContainer);
  }
}

bootstrapApplication(App);
```

stackblitz link for original code - https://stackblitz.com/edit/stackblitz-starters-dkwaqy?file=src%2Fmain.ts
stackblitz link after migration - https://stackblitz.com/edit/stackblitz-starters-27pd5u?file=src%2Fmain.ts

### Please provide a link to a minimal reproduction of the bug

https://stackblitz.com/edit/stackblitz-starters-27pd5u?file=src%2Fmain.ts

### Please provide the exception or error you saw

_No response_

### Please provide the environment you discovered this bug in (run `ng version`)

     _                      _                 ____ _     ___
    / \   _ __   __ _ _   _| | __ _ _ __     / ___| |   |_ _|
   / △ \ | '_ \ / _` | | | | |/ _` | '__|   | |   | |    | |
  / ___ \| | | | (_| | |_| | | (_| | |      | |___| |___ | |
 /_/   \_\_| |_|\__, |\__,_|_|\__,_|_|       \____|_____|___|
                |___/
    

Angular CLI: 18.0.5
Node: 18.20.3
Package Manager: npm 10.2.3
OS: linux x64

Angular: 18.0.4
... animations, common, compiler, compiler-cli, core, forms
... platform-browser, router

Package                         Version
---------------------------------------------------------
@angular-devkit/architect       0.1800.5
@angular-devkit/build-angular   18.0.5
@angular-devkit/core            18.0.5
@angular-devkit/schematics      18.0.5
@angular/cli                    18.0.5
@schematics/angular             18.0.5
rxjs                            7.8.1
typescript                      5.4.5
zone.js                         0.14.7

### Anything else?

_No response_