build: make a11y-demo compatible with ivy template type checking

Author: devversion

src/a11y-demo/checkbox/checkbox-a11y.html

@@ -20,12 +20,12 @@ <h2>Nested checklist</h2>
     <div *ngFor="let task of tasks">
       <mat-checkbox [(ngModel)]="task.completed"
                    [checked]="allComplete(task)"
-                   [indeterminate]="someComplete(task.subtasks)"
+                   [indeterminate]="someComplete(task.subtasks!)"
                    (change)="setAllCompleted(task.subtasks, $event.checked)">
         {{task.name}}
       </mat-checkbox>
       <div class="demo-sub-list">
-        <div *ngFor="let subtask of task.subtasks">
+        <div *ngFor="let subtask of task.subtasks!">
           <mat-checkbox [(ngModel)]="subtask.completed">
             {{subtask.name}}
           </mat-checkbox>

src/a11y-demo/chips/chips-a11y.ts

@@ -8,6 +8,7 @@
 
 import {Component} from '@angular/core';
 import {MatChipInputEvent, MatSnackBar} from '@angular/material';
+import {ThemePalette} from '@angular/material/core';
 
 
 export interface Person {
@@ -22,7 +23,7 @@ export interface Person {
 })
 export class ChipsAccessibilityDemo {
   visible: boolean = true;
-  color: string = '';
+  color: ThemePalette = undefined;
   selectable: boolean = true;
   removable: boolean = true;
   addOnBlur: boolean = true;

src/a11y-demo/grid-list/grid-list-a11y.ts

@@ -39,7 +39,7 @@ export class GridListAccessibilityDemo {
 
   fixedCols = 4;
   fixedRowHeight = 100;
-  ratioGutter = 1;
+  ratioGutter = '1px';
   fitListHeight = '400px';
   ratio = '4:1';
 }

src/a11y-demo/input/input-a11y.ts

@@ -24,7 +24,7 @@ export class InputAccessibilityDemo {
   email: string;
   usd: number;
   comment: string;
-  commentMax = 200;
+  commentMax = '200';
 
   get passwordType() { return this.showPassword ? 'text' : 'password'; }