[Templates] Updated app icons for net6 templates (#15237)

Co-authored-by: Manuel de la Pena <mandel@microsoft.com>
Co-authored-by: Rolf Bjarne Kvinge <rolf@xamarin.com>

dotnet/Templates/Microsoft.MacCatalyst.Templates/maccatalyst/AppDelegate.cs

@@ -17,7 +17,7 @@ public override bool FinishedLaunching (UIApplication application, NSDictionary
 		vc.View!.AddSubview (new UILabel (Window!.Frame) {
 			BackgroundColor = UIColor.SystemBackground,
 			TextAlignment = UITextAlignment.Center,
-			Text = "Hello, Catalyst!",
+			Text = "Hello, Mac Catalyst!",
 			AutoresizingMask = UIViewAutoresizing.All,
 		});
 		Window.RootViewController = vc;

dotnet/Templates/Microsoft.macOS.Templates/macos/Assets.xcassets/AppIcon.appiconset/Contents.json

@@ -1,68 +1,68 @@
 {
   "images": [
     {
-      "filename": "AppIcon-16.png",
-      "size": "16x16",
-      "scale": "1x",
-      "idiom": "mac"
+      "idiom" : "mac",
+      "scale" : "1x",
+      "size" : "16x16",
+      "filename": "Icon16.png"
     },
     {
-      "filename": "AppIcon-16@2x.png",
-      "size": "16x16",
-      "scale": "2x",
-      "idiom": "mac"
+      "idiom" : "mac",
+      "scale" : "2x",
+      "size" : "16x16",
+      "filename": "Icon32.png"
     },
     {
-      "filename": "AppIcon-32.png",
-      "size": "32x32",
-      "scale": "1x",
-      "idiom": "mac"
+      "idiom" : "mac",
+      "scale" : "1x",
+      "size" : "32x32",
+      "filename": "Icon32.png"
     },
     {
-      "filename": "AppIcon-32@2x.png",
-      "size": "32x32",
-      "scale": "2x",
-      "idiom": "mac"
+      "idiom" : "mac",
+      "scale" : "2x",
+      "size" : "32x32",
+      "filename": "Icon64.png"
     },
     {
-      "filename": "AppIcon-128.png",
-      "size": "128x128",
-      "scale": "1x",
-      "idiom": "mac"
+      "idiom" : "mac",
+      "scale" : "1x",
+      "size" : "128x128",
+      "filename": "Icon128.png"
     },
     {
-      "filename": "AppIcon-128@2x.png",
-      "size": "128x128",
-      "scale": "2x",
-      "idiom": "mac"
+      "idiom" : "mac",
+      "scale" : "2x",
+      "size" : "128x128",
+      "filename": "Icon256.png"
     },
     {
-      "filename": "AppIcon-256.png",
-      "size": "256x256",
-      "scale": "1x",
-      "idiom": "mac"
+      "idiom" : "mac",
+      "scale" : "1x",
+      "size" : "256x256",
+      "filename": "Icon256.png"
     },
     {
-      "filename": "AppIcon-256@2x.png",
-      "size": "256x256",
-      "scale": "2x",
-      "idiom": "mac"
+      "idiom" : "mac",
+      "scale" : "2x",
+      "size" : "256x256",
+      "filename": "Icon512.png"
     },
     {
-      "filename": "AppIcon-512.png",
-      "size": "512x512",
-      "scale": "1x",
-      "idiom": "mac"
+      "idiom" : "mac",
+      "scale" : "1x",
+      "size" : "512x512",
+      "filename": "Icon512.png"
     },
     {
-      "filename": "AppIcon-512@2x.png",
-      "size": "512x512",
-      "scale": "2x",
-      "idiom": "mac"
+      "idiom" : "mac",
+      "scale" : "2x",
+      "size" : "512x512",
+      "filename": "Icon1024.png"
     }
   ],
   "info": {
     "version": 1,
     "author": "xcode"
-  }
-}
+  },
+}