refactor(docs-infra): fix docs examples for tslint rules related to object properties (#38143)

This commit updates the docs examples to be compatible with the
`no-string-literal`, `object-literal-key-quotes` and
`object-literal-shorthand` tslint rules.

This is in preparation of updating the docs examples `tslint.json` to
match the one generated for new Angular CLI apps in a future commit.

PR Close #38143

aio/content/examples/dynamic-form/src/app/question-base.ts

@@ -10,13 +10,14 @@ export class QuestionBase<T> {
   options: {key: string, value: string}[];
 
   constructor(options: {
-      value?: T,
-      key?: string,
-      label?: string,
-      required?: boolean,
-      order?: number,
-      controlType?: string,
-      type?: string
+      value?: T;
+      key?: string;
+      label?: string;
+      required?: boolean;
+      order?: number;
+      controlType?: string;
+      type?: string;
+      options?: {key: string, value: string}[];
     } = {}) {
     this.value = options.value;
     this.key = options.key || '';
@@ -25,5 +26,6 @@ export class QuestionBase<T> {
     this.order = options.order === undefined ? 1 : options.order;
     this.controlType = options.controlType || '';
     this.type = options.type || '';
+    this.options = options.options || [];
   }
 }

aio/content/examples/dynamic-form/src/app/question-dropdown.ts

@@ -3,10 +3,4 @@ import { QuestionBase } from './question-base';
 
 export class DropdownQuestion extends QuestionBase<string> {
   controlType = 'dropdown';
-  options: {key: string, value: string}[] = [];
-
-  constructor(options: {} = {}) {
-    super(options);
-    this.options = options['options'] || [];
-  }
 }

aio/content/examples/dynamic-form/src/app/question-textbox.ts

@@ -3,10 +3,4 @@ import { QuestionBase } from './question-base';
 
 export class TextboxQuestion extends QuestionBase<string> {
   controlType = 'textbox';
-  type: string;
-
-  constructor(options: {} = {}) {
-    super(options);
-    this.type = options['type'] || '';
-  }
 }