fix(material-experimental/mdc-chips): replace innerText w/ textContent (angular#24635)

The chip edit input was using innerText to set the text of an element. This change was prompted by a Google-internal check that warns about `innerText`, but we generally want to use `textContent` anyway as it is more standard.

Author: jelbourn

src/material-experimental/mdc-chips/chip-edit-input.ts

@@ -38,7 +38,7 @@ export class MatChipEditInput {
   }
 
   setValue(value: string) {
-    this.getNativeElement().innerText = value;
+    this.getNativeElement().textContent = value;
     this._moveCursorToEndOfInput();
   }