Fix boolean condition to determine whether dynamic code is supported or not. Fixes #dotnet/runtime@101840. (#20563) (#20696)

Dynamic code is not supported if the interpreter is not enabled, and the
interpreter is not enabled if the MtouchInterpreter property is *empty*.

This regression was introduced in #19812.

Fixes https://github.com/dotnet/runtime/issues/101840.

dotnet/targets/Xamarin.Shared.Sdk.targets

@@ -143,7 +143,7 @@
 		<VerifyDependencyInjectionOpenGenericServiceTrimmability Condition="'$(VerifyDependencyInjectionOpenGenericServiceTrimmability)' == '' And '$(_BundlerDebug)' != 'true'">false</VerifyDependencyInjectionOpenGenericServiceTrimmability>
 		<VerifyDependencyInjectionOpenGenericServiceTrimmability Condition="'$(VerifyDependencyInjectionOpenGenericServiceTrimmability)' == ''">true</VerifyDependencyInjectionOpenGenericServiceTrimmability>
 		<!-- This should be set by dotnet/sdk instead, once https://github.com/dotnet/sdk/issues/25392 gets resolved.  -->
-		<DynamicCodeSupport Condition="'$(DynamicCodeSupport)' == '' And '$(MtouchInterpreter)' != '' And ('$(_PlatformName)' == 'iOS' Or '$(_PlatformName)' == 'tvOS' Or '$(_PlatformName)' == 'MacCatalyst')">false</DynamicCodeSupport>
+		<DynamicCodeSupport Condition="'$(DynamicCodeSupport)' == '' And '$(MtouchInterpreter)' == '' And ('$(_PlatformName)' == 'iOS' Or '$(_PlatformName)' == 'tvOS' Or '$(_PlatformName)' == 'MacCatalyst')">false</DynamicCodeSupport>
 
 		<!-- We don't need to generate reference assemblies for apps or app extensions -->
 		<ProduceReferenceAssembly Condition="'$(ProduceReferenceAssembly)' == '' And ('$(OutputType)' == 'Exe' Or '$(IsAppExtension)' == 'true')">false</ProduceReferenceAssembly>