如何为angular material选择添加全局默认panelClass？

.global-panel {
  background-color: #f2f2f2;
  border: 1px solid #ccc;
  padding: 10px;
}

import { InjectionToken } from '@angular/core';

export const GLOBAL_CONFIG = new InjectionToken<any>('globalConfig');

@NgModule({
  providers: [
    { provide: GLOBAL_CONFIG, useValue: { panelClass: 'global-panel' } }
  ]
})
export class AppModule { }

import { Component, Inject } from '@angular/core';
import { GLOBAL_CONFIG } from './app.module';

@Component({
  selector: 'app-my-component',
  template: `
    <mat-expansion-panel [panelClass]="globalConfig.panelClass">
      <!-- panel content -->
    </mat-expansion-panel>
  `
})
export class MyComponent {
  constructor(@Inject(GLOBAL_CONFIG) public globalConfig: any) { }
}