fix(material/legacy-button): rename classnames in comments (#25460)

Author: andrewseguin

src/material/legacy-button/testing/button-harness-filters.ts

@@ -8,7 +8,7 @@
 
 import {BaseHarnessFilters} from '@angular/cdk/testing';
 
-/** A set of criteria that can be used to filter a list of `MatLegacyButtonHarness` instances. */
+/** A set of criteria that can be used to filter a list of button harness instances. */
 export interface LegacyButtonHarnessFilters extends BaseHarnessFilters {
   /** Only find instances whose text matches the given value. */
   text?: string | RegExp;