title: mat-sidenav-content is throwing No provider for MatSidenavContainer
body: <p><strong>app.component.html</strong></p>
  
  <pre><code>&lt;mat-side-nav-container&gt;
  
      &lt;mat-sidenav #sidenav&gt;
          &lt;mat-nav-list&gt;
              &lt;a mat-list-item [routerLink]="'/accounts'"&gt; Accounts &lt;/a&gt;
              &lt;a mat-list-item [routerLink]="'/create-account'"&gt; Create Account &lt;/a&gt;
              &lt;a mat-list-item [routerLink]="'/contacts'"&gt; Contacts &lt;/a&gt;
              &lt;a mat-list-item [routerLink]="'/create-contact'"&gt; Create Contact &lt;/a&gt;
              &lt;a mat-list-item [routerLink]="'/activities'"&gt; Activities &lt;/a&gt;
              &lt;a mat-list-item [routerLink]="'/create-activity'"&gt; Create Activity &lt;/a&gt;
              &lt;a mat-list-item (click)="sidenav.toggle()" href="" mat-list-item&gt;Close&lt;/a&gt;
          &lt;/mat-nav-list&gt;
      &lt;/mat-sidenav&gt;
      &lt;mat-sidenav-content&gt;&lt;/mat-sidenav-content&gt;
  &lt;/mat-side-nav-container&gt;
  </code></pre>
  
  <p><strong>app.moule.ts</strong></p>
  
  <pre><code>@NgModule({
    declarations: [
      AppComponent,
    ],
    imports: [
      BrowserModule,
      BrowserAnimationsModule,    
      MatToolbarModule,
      MatSidenavModule,
      MatListModule,
      MatButtonModule,
      MatIconModule,
      HttpClientModule,
      AppRoutingModule,
    ],
    providers: [],
    bootstrap: [AppComponent],
    schemas: [CUSTOM_ELEMENTS_SCHEMA]
  })
  export class AppModule { }
  </code></pre>
  
  <p><strong>MatSidenavModulemodule</strong> is imported but still getting the below error</p>
  
  <blockquote>
    <p>NullInjectorError: StaticInjectorError(AppModule)[MatSidenavContent ->
    MatSidenavContainer]:    StaticInjectorError(Platform:
    core)[MatSidenavContent -> MatSidenavContainer]: 
        NullInjectorError: No provider for MatSidenavContainer!</p>
  </blockquote>