[net6] Consolidate feature switches defaults (#5662)

Context: https://github.com/dotnet/runtime/blob/d0616f837f4ad1ceb7e36a341934c929fd790089/docs/workflow/trimming/feature-switches.md

Move all the feature switches default settings to one place.

src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.DefaultProperties.targets

@@ -61,8 +61,23 @@
     <AndroidManifest Condition=" '$(AndroidManifest)' == '' ">AndroidManifest.xml</AndroidManifest>
     <GenerateApplicationManifest Condition=" '$(GenerateApplicationManifest)' == '' ">true</GenerateApplicationManifest>
 
-    <!-- Enable/Disable default runtime features-->
+    <!--
+      Runtime libraries feature switches defaults
+      Available feature switches: https://github.com/dotnet/runtime/blob/master/docs/workflow/trimming/feature-switches.md
+     -->
+    <DebuggerSupport Condition="'$(DebuggerSupport)' == ''">$(AndroidUseDebugRuntime)</DebuggerSupport>
+    <EnableUnsafeUTF7Encoding Condition="'$(EnableUnsafeUTF7Encoding)' == ''">false</EnableUnsafeUTF7Encoding>
+    <EnableUnsafeBinaryFormatterSerialization Condition="'$(EnableUnsafeBinaryFormatterSerialization)' == ''">false</EnableUnsafeBinaryFormatterSerialization>
+    <EventSourceSupport Condition="'$(EventSourceSupport)' == ''">false</EventSourceSupport>
+    <InvariantGlobalization Condition="'$(InvariantGlobalization)' == ''">false</InvariantGlobalization>
+    <UseSystemResourceKeys Condition="'$(UseSystemResourceKeys)' == ''">true</UseSystemResourceKeys>
+    <HttpActivityPropagationSupport Condition="'$(HttpActivityPropagationSupport)' == ''">false</HttpActivityPropagationSupport>
+    <StartupHookSupport Condition="'$(StartupHookSupport)' == ''">false</StartupHookSupport>
     <UseNativeHttpHandler Condition="'$(UseNativeHttpHandler)' == ''">true</UseNativeHttpHandler>
+
+    <!-- XA feature switches defaults -->
+    <XATypeRegistrationFallback Condition="'$(XATypeRegistrationFallback)' == ''">false</XATypeRegistrationFallback>
+
   </PropertyGroup>
   <PropertyGroup Condition=" '$(AndroidApplication)' == 'true' and '$(GenerateApplicationManifest)' == 'true' ">
     <ApplicationVersion Condition=" '$(ApplicationVersion)' == '' ">1.0</ApplicationVersion>

src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.ILLink.targets

@@ -9,22 +9,6 @@ This file contains the .NET 5-specific targets to customize ILLink
 
 <Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 
-  <PropertyGroup>
-    <!--
-      Runtime libraries feature switches defaults
-      Available feature switches: https://github.com/dotnet/runtime/blob/master/docs/workflow/trimming/feature-switches.md
-     -->
-    <DebuggerSupport Condition="'$(DebuggerSupport)' == ''">$(AndroidUseDebugRuntime)</DebuggerSupport>
-    <EnableUnsafeUTF7Encoding Condition="'$(EnableUnsafeUTF7Encoding)' == ''">false</EnableUnsafeUTF7Encoding>
-    <EnableUnsafeBinaryFormatterSerialization Condition="'$(EnableUnsafeBinaryFormatterSerialization)' == ''">false</EnableUnsafeBinaryFormatterSerialization>
-    <EventSourceSupport Condition="'$(EventSourceSupport)' == ''">false</EventSourceSupport>
-    <InvariantGlobalization Condition="'$(InvariantGlobalization)' == ''">false</InvariantGlobalization>
-    <UseSystemResourceKeys Condition="'$(UseSystemResourceKeys)' == ''">true</UseSystemResourceKeys>
-    <HttpActivityPropagationSupport Condition="'$(HttpActivityPropagationSupport)' == ''">false</HttpActivityPropagationSupport>
-    <StartupHookSupport Condition="'$(StartupHookSupport)' == ''">false</StartupHookSupport>
-    <XATypeRegistrationFallback Condition="'$(XATypeRegistrationFallback)' == ''">false</XATypeRegistrationFallback>
-  </PropertyGroup>
-
   <Target Name="_PrepareLinking"
       Condition=" '$(PublishTrimmed)' == 'true' "
       AfterTargets="ComputeResolvedFilesToPublishList"