[.NET 6] Add API 33 packs to android workload (#7169)

After backporting stable API 33 bindings, projects that use any of our
net6.0-android target framework framework variants (net6.0-android,
net6.0-android32) will attempt to use API 33 runtime packs.

Now that API 33 is stable, we should include all of these packs in the
"default" `android` workload so that they will always be installed.

The `android-33` workload has been preserved as an empty extension of
`android` to prevent any issues that may arise from removing an already
established workload ID from the .NET 6.0.300 and 6.0.400 bands.

Author: pjcollins

src/Xamarin.Android.Build.Tasks/Microsoft.NET.Sdk.Android/WorkloadManifest.in.json

@@ -7,24 +7,18 @@
         "Microsoft.Android.Sdk",
         "Microsoft.Android.Ref.31",
         "Microsoft.Android.Ref.32",
-        "Microsoft.Android.Runtime.32.android-arm",
-        "Microsoft.Android.Runtime.32.android-arm64",
-        "Microsoft.Android.Runtime.32.android-x86",
-        "Microsoft.Android.Runtime.32.android-x64",
+        "Microsoft.Android.Ref.33",
+        "Microsoft.Android.Runtime.33.android-arm",
+        "Microsoft.Android.Runtime.33.android-arm64",
+        "Microsoft.Android.Runtime.33.android-x86",
+        "Microsoft.Android.Runtime.33.android-x64",
         "Microsoft.Android.Templates"
       ],
       "platforms": [ "win-x64", "win-arm64", "linux-x64", "osx-x64", "osx-arm64" ],
       "extends" : [ "microsoft-net-runtime-android", "microsoft-net-runtime-android-aot" ]
     },
     "android-33": {
       "description": "Support for Android API-33.",
-      "packs": [
-        "Microsoft.Android.Ref.33",
-        "Microsoft.Android.Runtime.33.android-arm",
-        "Microsoft.Android.Runtime.33.android-arm64",
-        "Microsoft.Android.Runtime.33.android-x86",
-        "Microsoft.Android.Runtime.33.android-x64"
-      ],
       "platforms": [ "win-x64", "win-arm64", "linux-x64", "osx-x64", "osx-arm64" ],
       "extends" : [ "android" ]
     }