[nz-select] select option is not active after dynamically changing select source on (nzOnSearch)

[tky753]

Reproduction link

https://stackblitz.com/edit/nz-table-dynamic-active?file=src/app/app.component.ts

Steps to reproduce

1. copy "shen" to static nz-select
2. copy "shen" to dynamic nz-select
   

What is expected?

select option "shenzhen" is active for both compoments.

What is actually happening?

select option "shenzhen" is active for static nz-select,
but select option "shenzhen" is not active for dynamic nz-select.

Environment	Info
ng-zorro-antd	8.3.1
Browser	Chrome 76.0.3809.132（正式版本） （64 位）

---

After copying value to nz-select compoment, I have to tap down arrow to active the select option even if there is only one option.

[wenqi73]

  constructor(private cdr: ChangeDetectorRef) {}
  onSearch(val: string) {
    // ...
    this.cdr.detectChanges();
  }