fix(material/chips): add aria-hidden

add aria-hidden to host mat-chip so Talkback ignores element

fixes b/286286473

Author: DBowen33

src/material/chips/chip-row.spec.ts

@@ -102,7 +102,7 @@ describe('MDC-based Row Chips', () => {
       });
 
       it('should have the correct role', () => {
-        expect(chipNativeElement.getAttribute('role')).toBe('presentation');
+        expect(chipNativeElement.getAttribute('role')).toBe('row');
       });
 
       it('should be able to set a custom role', () => {

src/material/chips/chip.ts

@@ -87,6 +87,7 @@ export interface MatChipEvent {
     '[attr.role]': 'role',
     '[attr.tabindex]': '_getTabIndex()',
     '[attr.aria-label]': 'ariaLabel',
+    '[attr.aria-hidden]': 'true',
     '(keydown)': '_handleKeydown($event)',
   },
   encapsulation: ViewEncapsulation.None,
@@ -280,7 +281,6 @@ export class MatChip implements OnInit, AfterViewInit, AfterContentInit, DoCheck
     this._isBasicChip =
       element.hasAttribute(this.basicChipAttrName) ||
       element.tagName.toLowerCase() === this.basicChipAttrName;
-    this.role = 'presentation';
   }
 
   ngAfterViewInit() {