[XBD] Changing XBD MasterBeforeTargets value on .net6.0-ios builds

With .net6.0-ios builds, executing XBD before GetFrameworkPaths target
is too late.

At this point frameworks bundles downloaded with XBD are embedded
correctly to the build but not processed nor copied to the final .app
due to _CollectBundleResources target is executed once and way before
GetFrameworkPaths on .net6.0.

Although _CollectBundleResources target is called multiple times during
the build, with .net6.0 it's designed to be executed once per RID to
save time.

This PR overrides the MasterBeforeTargets property with .net6.0 builds
so stuff downloaded using XBD are embedded at a proper time.

Util/Xamarin.Build.Download/source/Xamarin.Build.Download/Xamarin.Build.Download.csproj

@@ -8,7 +8,7 @@
 
  <PackageId>Xamarin.Build.Download</PackageId>
  <Title>Xamarin Build-time Download Support</Title>
- <PackageVersion>0.11.0</PackageVersion>
+ <PackageVersion>0.11.1</PackageVersion>
  <Authors>Microsoft</Authors>
  <Owners>Microsoft</Owners>
  <PackageProjectUrl>https://go.microsoft.com/fwlink/?linkid=865061</PackageProjectUrl>

Util/Xamarin.Build.Download/source/Xamarin.Build.Download/Xamarin.Build.Download.targets

@@ -12,6 +12,7 @@
 
  <PropertyGroup Condition="('$(TargetFrameworkIdentifier)'=='Xamarin.iOS' or '$(TargetPlatformIdentifier)'=='ios') and ('$(OutputType)' != 'Library' or '$(IsAppExtension)'=='True')">
  <_XamarinBuildDownloadMasterBeforeTargets>GetFrameworkPaths</_XamarinBuildDownloadMasterBeforeTargets>
+ <_XamarinBuildDownloadMasterBeforeTargets Condition="$(TargetFramework.Contains('-ios'))">_BeforeCoreCompileInterfaceDefinitions</_XamarinBuildDownloadMasterBeforeTargets>
  <_XamarinBuildDownloadMasterDependsOnTargets>_XamarinBuildDownload;_XamarinBuildCastAssemblyResources</_XamarinBuildDownloadMasterDependsOnTargets>
  </PropertyGroup>