build: update to angular-v9.1.12 (#1215)

Fixes: #1216

src/app/self-service/users/users.component.ts

@@ -2,7 +2,9 @@
 import { Component, OnInit, ViewChild } from '@angular/core';
 import { ActivatedRoute } from '@angular/router';
 import { SelectionModel } from '@angular/cdk/collections';
-import { MatPaginator, MatSort, MatTableDataSource } from '@angular/material';
+import { MatPaginator } from '@angular/material/paginator';
+import { MatSort } from '@angular/material/sort';
+import { MatTableDataSource } from '@angular/material/table';
 
 /** Custom Services */
 import { UserService } from './user.service';
@@ -32,9 +34,9 @@ export class UsersComponent implements OnInit {
   selection = new SelectionModel<User>(true, []);
 
   /** Paginator for users table. */
-  @ViewChild(MatPaginator) paginator: MatPaginator;
+  @ViewChild(MatPaginator, { static: true }) paginator: MatPaginator;
   /** Sorter for users table. */
-  @ViewChild(MatSort) sort: MatSort;
+  @ViewChild(MatSort, { static: true }) sort: MatSort;
 
   /**
    * Retrieves the users data from `resolve`.