fix(material/chips): fixes chips input demo moving input out of chip-grid

Updates previous chips-demo.html so that the input element is not a child
of chip-grid, but rather a sibling. When mat-chip-grid contains the input,
it hides this as an interactive element from mobile Voice Controls making
it inaccessible.

Fixes b/380092814

Author: essjay05

src/dev-app/chips/chips-demo.html

@@ -184,12 +184,12 @@ <h4>Input is last child of chip grid</h4>
               </button>
             </mat-chip-row>
           }
-          <input [disabled]="disableInputs"
-                 [matChipInputFor]="chipGrid1"
-                 [matChipInputSeparatorKeyCodes]="separatorKeysCodes"
-                 [matChipInputAddOnBlur]="addOnBlur"
-                 (matChipInputTokenEnd)="add($event)" />
         </mat-chip-grid>
+        <input [disabled]="disableInputs"
+                [matChipInputFor]="chipGrid1"
+                [matChipInputSeparatorKeyCodes]="separatorKeysCodes"
+                [matChipInputAddOnBlur]="addOnBlur"
+                (matChipInputTokenEnd)="add($event)" />
       </mat-form-field>
 
       <h4>Input is next sibling child of chip grid</h4>