refactor(focus-monitor): adapt demo examples for Ivy

Author: marclaval

src/material-examples/focus-monitor-focus-via/focus-monitor-focus-via-example.ts

@@ -16,7 +16,7 @@ import {
   styleUrls: ['focus-monitor-focus-via-example.css']
 })
 export class FocusMonitorFocusViaExample implements OnDestroy, OnInit {
-  @ViewChild('monitored') monitoredEl: ElementRef<HTMLElement>;
+  @ViewChild('monitored', {static: true}) monitoredEl: ElementRef<HTMLElement>;
 
   origin = this.formatOrigin(null);
 

src/material-examples/focus-monitor-overview/focus-monitor-overview-example.ts

@@ -16,8 +16,8 @@ import {
   styleUrls: ['focus-monitor-overview-example.css']
 })
 export class FocusMonitorOverviewExample implements OnDestroy, OnInit {
-  @ViewChild('element') element: ElementRef<HTMLElement>;
-  @ViewChild('subtree') subtree: ElementRef<HTMLElement>;
+  @ViewChild('element', {static: true}) element: ElementRef<HTMLElement>;
+  @ViewChild('subtree', {static: true}) subtree: ElementRef<HTMLElement>;
 
   elementOrigin = this.formatOrigin(null);
   subtreeOrigin = this.formatOrigin(null);