title: Property binding matHeaderRowDef not used by any directive on an embedded template
body: <p>Here is the table html:</p>
  <pre class="lang-html prettyprint-override"><code>&lt;mat-table matSort class=&quot;inbox__messages&quot; #table [dataSource]=&quot;dataSource&quot;&gt;
  
  &lt;!-- Building Column --&gt;
  &lt;ng-container matColumnDef=&quot;building&quot;&gt;
    &lt;mat-header-cell *matHeaderCellDef&gt;
    &lt;div class=&quot;inbox__messages__header&quot;&gt;
      &lt;h3 class=&quot;inbox__messages__header-label&quot;&gt;Bâtiments&lt;/h3&gt;
      &lt;mat-form-field class=&quot;inbox__messages__dropdown&quot;&gt;
        &lt;mat-select placeholder=&quot;Choisir un bâtiment&quot;&gt;
          &lt;mat-option *ngFor=&quot;let building of buildings&quot; [value]=&quot;building.value&quot;&gt;
            {{ building.viewValue }}
          &lt;/mat-option&gt;
        &lt;/mat-select&gt;
      &lt;/mat-form-field&gt;
    &lt;/div&gt;
    &lt;/mat-header-cell&gt;
    &lt;mat-cell *matCellDef=&quot;let element&quot;&gt;
    &lt;span class=&quot;inbox__messages__body-building&quot;&gt;{{element.building}}&lt;/span&gt;
  &lt;/mat-cell&gt;
  &lt;/ng-container&gt;
  
   &lt;mat-header-row *matHeaderRowDef=&quot;displayedColumns&quot;&gt;&lt;/mat-header-row&gt;
  &lt;mat-row *matRowDef=&quot;let row; columns: displayedColumns;&quot; matRipple class=&quot;element-row&quot; [class.expanded]=&quot;expandedElement == row&quot;
  (click)=&quot;expandedElement = row&quot;&gt;&lt;/mat-row&gt;
  </code></pre>
  
  <p>This error happens on ng test. What am I missing? I have imported MatHeaderRowDef into my component aswell as into the module.</p>