docs: Remove of unnecessary Input (#41150)

remove unnecessary Input

PR Close #41150

aio/content/examples/attribute-directives/src/app/highlight.directive.2.ts

@@ -26,9 +26,6 @@ export class HighlightDirective {
     this.el.nativeElement.style.backgroundColor = color;
   }
   // #enddocregion mouse-methods
-  // #docregion color-2
-  @Input() appHighlight: string;
-  // #enddocregion color-2
 
 }
 // #enddocregion

aio/content/examples/attribute-directives/src/app/highlight.directive.3.ts

@@ -10,10 +10,12 @@ export class HighlightDirective {
 
   constructor(private el: ElementRef) { }
 
-  @Input('appHighlight') highlightColor: string;
+  // #docregion input
+  @Input() appHighlight: string;
+  // #enddocregion input
 
   @HostListener('mouseenter') onMouseEnter() {
-    this.highlight(this.highlightColor || 'red');
+    this.highlight(this.appHighlight || 'red');
   }
 
   @HostListener('mouseleave') onMouseLeave() {

aio/content/guide/attribute-directives.md

@@ -91,7 +91,7 @@ This section walks you through setting the highlight color while applying the `H
 
 1. Add an `appHighlight` `@Input()` property.
 
-  <code-example path="attribute-directives/src/app/highlight.directive.2.ts" header="src/app/highlight.directive.ts" region="color-2"></code-example>
+  <code-example path="attribute-directives/src/app/highlight.directive.3.ts" header="src/app/highlight.directive.ts" region="input"></code-example>
 
   The `@Input()` decorator adds metadata to the class that makes the directive's `appHighlight` property available for binding.