fix(material/chips): wait for onStable when editing a chip

Address timing issue with MatChipRow. When a chip enters the editing
state wait for ngZone's `onStable` event before accessing the ViewChild
for the MatChipEditInput. Attempts to fix issue where editable chip goes
blank when entering the editing state (#27462).

What seemed to be happening is that the view would render the
MatChiEditInput when setting `_isEditing` to true, but sometimes the
ViewChild would not be initialized in the component. Address this issue
by adding additional wait using `_ngZone.onStable`.

Fix #27462.

Author: zarend

src/material/chips/chip-row.ts

@@ -30,7 +30,7 @@ import {MAT_RIPPLE_GLOBAL_OPTIONS, RippleGlobalOptions} from '@angular/material/
 import {FocusMonitor} from '@angular/cdk/a11y';
 import {MatChip, MatChipEvent} from './chip';
 import {MatChipEditInput} from './chip-edit-input';
-import {takeUntil} from 'rxjs/operators';
+import {take, takeUntil} from 'rxjs/operators';
 import {MAT_CHIP} from './tokens';
 
 /** Represents an event fired on an individual `mat-chip` when it is edited. */
@@ -183,8 +183,12 @@ export class MatChipRow extends MatChip implements AfterViewInit {
 
     // Defer initializing the input so it has time to be added to the DOM.
     setTimeout(() => {
-      this._getEditInput().initialize(value);
-      this._editStartPending = false;
+      this._ngZone.onStable.pipe(take(1)).subscribe({
+        next: () => {
+          this._getEditInput().initialize(value);
+          this._editStartPending = false;
+        },
+      });
     });
   }