docs(material/divider): Update divider examples (#29243)

(cherry picked from commit 5ba7a0e)

Author: mmalerba

src/components-examples/material/divider/divider-harness/divider-harness-example.ts

@@ -1,4 +1,4 @@
-import {Component} from '@angular/core';
+import {ChangeDetectionStrategy, Component} from '@angular/core';
 import {MatDividerModule} from '@angular/material/divider';
 
 /**
@@ -9,5 +9,6 @@ import {MatDividerModule} from '@angular/material/divider';
   templateUrl: 'divider-harness-example.html',
   standalone: true,
   imports: [MatDividerModule],
+  changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class DividerHarnessExample {}

src/components-examples/material/divider/divider-overview/divider-overview-example.ts

@@ -1,4 +1,4 @@
-import {Component} from '@angular/core';
+import {ChangeDetectionStrategy, Component} from '@angular/core';
 import {MatDividerModule} from '@angular/material/divider';
 import {MatListModule} from '@angular/material/list';
 
@@ -10,5 +10,6 @@ import {MatListModule} from '@angular/material/list';
   templateUrl: 'divider-overview-example.html',
   standalone: true,
   imports: [MatListModule, MatDividerModule],
+  changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class DividerOverviewExample {}