title: service not singleton inside MatDialog module
body: <p>When I open a Mat Dialog popup ( angular material ) and accessing a singleton service, for some reason inside the mat dialog the service seems to be a new instance of the service and not the singleton service used across the app.</p>
  
  <p>I know how to make workaround but I prefer understanding if there is a known issue with matdialog and maybe a fix.</p>
  
  <pre><code>  const dialogRef = this.dialog.open(MyComponent, {
    width: '400px',
    data: {
      myInfo: Info
    },
  });
  </code></pre>
  
  <p>The service was added in the "App.component.ts" as a singleton like this:</p>
  
  <pre><code>import {Component, OnInit} from '@angular/core';
  import {NavigationEnd, Router} from '@angular/router';
  import {AuthService} from './shared/services/auth.service';
  @Component({  selector: 'app-root',  templateUrl: './app.component.html',  styleUrls: ['./app.component.scss'],  
  
  providers: [AuthService]})    export class AppComponent implements OnInit {}
  </code></pre>
  
  <p>Thanks!</p>