Update example app icon with latest IG branding

Summary:
Updates the app icon for the IGListKit iOS example app with a more modern look to reflect Instagram's style refresh in 2022.

- The shape of the bars are rounded with Apple's superellipse style and the radius is adjusted to match the curvature of the app icon itself.
- The bars now show the official Instagram 5-color gradient pattern that was released as part of the 2022 brand refresh.

Differential Revision: D56872824

fbshipit-source-id: c811754b6787d2bd15eee53b12eaa61d6cdaf367

Examples/Examples-iOS/IGListKitExamples/Assets.xcassets/AppIcon.appiconset/Contents.json

@@ -1,62 +1,14 @@
 {
   "images" : [
     {
-      "size" : "20x20",
-      "idiom" : "iphone",
-      "filename" : "Icon-App-40x40@1x.png",
-      "scale" : "2x"
-    },
-    {
-      "size" : "20x20",
-      "idiom" : "iphone",
-      "filename" : "Icon-App-60x60@1x.png",
-      "scale" : "3x"
-    },
-    {
-      "size" : "29x29",
-      "idiom" : "iphone",
-      "filename" : "Icon-App-29x29@2x.png",
-      "scale" : "2x"
-    },
-    {
-      "size" : "29x29",
-      "idiom" : "iphone",
-      "filename" : "Icon-App-29x29@3x.png",
-      "scale" : "3x"
-    },
-    {
-      "size" : "40x40",
-      "idiom" : "iphone",
-      "filename" : "Icon-App-40x40@2x.png",
-      "scale" : "2x"
-    },
-    {
-      "size" : "40x40",
-      "idiom" : "iphone",
-      "filename" : "Icon-App-40x40@3x.png",
-      "scale" : "3x"
-    },
-    {
-      "size" : "60x60",
-      "idiom" : "iphone",
-      "filename" : "Icon-App-60x60@2x.png",
-      "scale" : "2x"
-    },
-    {
-      "size" : "60x60",
-      "idiom" : "iphone",
-      "filename" : "Icon-App-60x60@3x.png",
-      "scale" : "3x"
-    },
-    {
-      "size" : "1024x1024",
-      "idiom" : "ios-marketing",
-      "filename" : "Icon-App-1024x1024.png",
-      "scale" : "1x"
+      "filename" : "AppIcon.png",
+      "idiom" : "universal",
+      "platform" : "ios",
+      "size" : "1024x1024"
     }
   ],
   "info" : {
-    "version" : 1,
-    "author" : "xcode"
+    "author" : "xcode",
+    "version" : 1
   }
-}
+}