Fix the name of the item function. (xamarin#18199)

The name is `HasMetadata`, not `HasMetadataValue`
(https://learn.microsoft.com/en-us/visualstudio/msbuild/item-functions?view=vs-2022).

dotnet/targets/Xamarin.Shared.Sdk.targets

@@ -461,7 +461,7 @@
 				 1. The global TrimMode property is set to 'copy'
 				 2. No assembly has the TrimMode metadata (unless it's set to 'copy')
 			-->
-			<_AssembliesWithCustomTrimMode>@(ManagedAssemblyToLink->HasMetadataValue('TrimMode')->Count())</_AssembliesWithCustomTrimMode>
+			<_AssembliesWithCustomTrimMode>@(ManagedAssemblyToLink->HasMetadata('TrimMode')->Count())</_AssembliesWithCustomTrimMode>
 			<_AssembliesWithCopyTrimMode>@(ManagedAssemblyToLink->WithMetadataValue('TrimMode', 'copy')->Count())</_AssembliesWithCopyTrimMode>
 			<_AreAnyAssembliesTrimmed Condition="'$(_AreAnyAssembliesTrimmed)' == '' And '$(TrimMode)' == 'copy' And '$(_AssembliesWithCustomTrimMode)' == '$(_AssembliesWithCopyTrimMode)'">false</_AreAnyAssembliesTrimmed>
 			<_AreAnyAssembliesTrimmed Condition="'$(_AreAnyAssembliesTrimmed)' == ''">true</_AreAnyAssembliesTrimmed>