chore(demo): update chip input demo (#7526)

Author: amcdnl

src/material-examples/chips-input/chips-input-example.html

@@ -1,14 +1,14 @@
 <mat-form-field class="demo-chip-list">
-  <mat-chip-list matPrefix #chipList>
+  <mat-chip-list #chipList>
     <mat-chip *ngFor="let fruit of fruits" [selectable]="selectable"
              [removable]="removable" (remove)="remove(fruit)">
       {{fruit.name}}
       <mat-icon matChipRemove *ngIf="removable">cancel</mat-icon>
     </mat-chip>
+    <input placeholder="New fruit..."
+           [matChipInputFor]="chipList"
+           [matChipInputSeparatorKeyCodes]="separatorKeysCodes"
+           [matChipInputAddOnBlur]="addOnBlur"
+           (matChipInputTokenEnd)="add($event)" />
   </mat-chip-list>
-  <input matInput placeholder="New fruit..."
-         [matChipInputFor]="chipList"
-         [matChipInputSeparatorKeyCodes]="separatorKeysCodes"
-         [matChipInputAddOnBlur]="addOnBlur"
-         (matChipInputTokenEnd)="add($event)" />
 </mat-form-field>