fix(aio): remove unused icon reference and file

These icons are not there (and never were afaict).

Fixes #17561

aio/src/assets/images/favicons/manifest.json

@@ -1,41 +0,0 @@
-{
-	"name": "Angular.io",
-	"icons": [
-		{
-			"src": "\/android-chrome-36x36.png",
-			"sizes": "36x36",
-			"type": "image\/png",
-			"density": "0.75"
-		},
-		{
-			"src": "\/android-chrome-48x48.png",
-			"sizes": "48x48",
-			"type": "image\/png",
-			"density": "1.0"
-		},
-		{
-			"src": "\/android-chrome-72x72.png",
-			"sizes": "72x72",
-			"type": "image\/png",
-			"density": "1.5"
-		},
-		{
-			"src": "\/android-chrome-96x96.png",
-			"sizes": "96x96",
-			"type": "image\/png",
-			"density": "2.0"
-		},
-		{
-			"src": "\/android-chrome-144x144.png",
-			"sizes": "144x144",
-			"type": "image\/png",
-			"density": "3.0"
-		},
-		{
-			"src": "\/android-chrome-192x192.png",
-			"sizes": "192x192",
-			"type": "image\/png",
-			"density": "4.0"
-		}
-	]
-}

aio/src/index.html

@@ -15,8 +15,6 @@
         sizes="194x194">
   <link rel="icon" type="image/png" href="assets/images/favicons/favicon-96x96.png"
         sizes="96x96">
-  <link rel="icon" type="image/png" href="assets/images/favicons/android-chrome-192x192.png"
-        sizes="192x192">
   <link rel="icon" type="image/png" href="assets/images/favicons/favicon-16x16.png"
         sizes="16x16">
   <link rel="apple-touch-icon" sizes="144x144" href="assets/images/favicons/apple-touch-icon-144x144.png">
@@ -32,7 +30,7 @@
   <meta name="theme-color" content="#1976d2">
   <meta name="apple-mobile-web-app-capable" content="yes">
   <meta name="apple-mobile-web-app-status-bar-style" content="translucent">
-  
+
 
   <!-- Google Analytics -->
   <script>