fix(tree): fix nested node is not working

Author: tinayuangao

src/lib/tree/node.ts

@@ -101,4 +101,12 @@ export class MatNestedTreeNode<T> extends _MatNestedTreeNodeMixinBase<T>
 
     this.tabIndex = Number(tabIndex) || 0;
   }
+
+  ngAfterContentInit() {
+    super.ngAfterContentInit();
+  }
+
+  ngOnDestroy() {
+    super.ngOnDestroy();
+  }
 }