title: mat-toolbar not match width with mat-sidenav
body: <p>Learning angular material design. I created a side-nav and inside it i placed a mat-toolbar, but mat-tool bar not taking the full-width of its parent side-nav, showing some white line on its right side ( which is the background colour of its parent) 
  How can I remove the white background </p>
  
  <p><a href="https://i.stack.imgur.com/HVzDz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/HVzDz.png" alt="https://i.imgur.com/TaYIzjd.png"></a></p>
  
  <p>main-nav.component.html</p>
  
  <pre><code>`&lt;mat-sidenav-container class="sidenav-container"&gt;
    &lt;mat-sidenav #drawer class="sidenav" fixedInViewport="true"
        [attr.role]="(isHandset$ | async) ? 'dialog' : 'navigation'"
        [mode]="(isHandset$ | async) ? 'over' : 'side'"
        [opened]="!(isHandset$ | async)"&gt;
        &lt;mat-toolbar color="primary"&gt;Menu
        &lt;/mat-toolbar&gt;
      &lt;mat-nav-list&gt;
        &lt;a mat-list-item href="#"&gt;Link 1&lt;/a&gt;
        &lt;a mat-list-item href="#"&gt;Link 2&lt;/a&gt;
        &lt;a mat-list-item href="#"&gt;Link 3&lt;/a&gt;
      &lt;/mat-nav-list&gt;
    &lt;/mat-sidenav&gt;
    &lt;mat-sidenav-content&gt;
      &lt;mat-toolbar color="primary"&gt;
        &lt;button
          type="button"
          aria-label="Toggle sidenav"
          mat-icon-button
          (click)="drawer.toggle()"
          *ngIf="isHandset$ | async"&gt;
          &lt;mat-icon aria-label="Side nav toggle icon"&gt;menu&lt;/mat-icon&gt;
        &lt;/button&gt;
        &lt;span&gt;printhouse&lt;/span&gt;
      &lt;/mat-toolbar&gt;
      &lt;ng-content&gt;&lt;/ng-content&gt;
    &lt;/mat-sidenav-content&gt;
  &lt;/mat-sidenav-container&gt;`
  </code></pre>
  
  <p>main-nav.component.css</p>
  
  <pre><code>.sidenav-container {
    height: 100%;
  }
  
  .sidenav {
    width: 200px;
   box-shadow:  2px 0 6px rgba(0,0,0,0.24);
  
  }
  
  .sidenav .mat-toolbar {
    /* background: inherit; */
  
   }
  
  
  .mat-toolbar.mat-primary {
    position:sticky;
    top: 0;
    z-index: 1;
  
  }
  </code></pre>
  
  <p>How can I remove the white background</p>