title: No provider for MatExpansionPanel if used inside child component in *ngFor
body: <p>I want to separate my mat-accordion from each of the mat-expansion-panel using child component.</p>
  
  <p>my app.component.html looks like this:</p>
  
  <pre><code>&lt;mat-accordion&gt;
    &lt;mat-expansion-panel *ngFor="let customer of customers"&gt;
      &lt;app-customer [name]="customer"&gt;&lt;/app-customer&gt;
    &lt;/mat-expansion-panel&gt;
  &lt;/mat-accordion&gt;
  </code></pre>
  
  <p>My child component looks like this:</p>
  
  <pre><code>&lt;mat-expansion-panel-header&gt;
        {{ name }}
  &lt;/mat-expansion-panel-header&gt;
  </code></pre>
  
  <p>When i start the application i get the following error in console (and nothing is displayed)</p>
  
  <pre><code>Uncaught Error: Template parse errors:
  No provider for MatExpansionPanel ("[ERROR -&gt;]&lt;mat-expansion-panel-header&gt;
        {{ name }}
  &lt;/mat-expansion-panel-header&gt;
  "): ng:///AppModule/CustomerComponent.html@0:0
  </code></pre>
  
  <p>What am I doing wrong? If I don't use a child component, it works okay</p>