[xamlc] enable for $(Configuration) names like ReleaseProd (#14638)

Context: #14591 (comment)

In testing a customer project, I found that using a non-standard
`$(Configuration)` name like `ReleaseProd` disables XamlC.

In a30e243, we added a check for `$(Configuration)` to be exactly
`Release`. Let's invert this check to be `!= Debug`. I also added a
test to verify this works.

This seems like a better default for customers, as it seems a lot
worse for a `ReleaseProd` build to have XamlC off than a `DebugProd`
build to accidentally have XamlC on.

Asking around, but the .NET SDK doesn't appear to do anything special
for `$(Optimize)` and `$(DebugSymbols)` related to `$(Configuration)`:

https://github.com/dotnet/sdk/blob/7d23e9d3e4aad58a5b497d8d91a50ffdf148b238/src/Tasks/Microsoft.NET.Build.Tasks/targets/Microsoft.NET.Sdk.props#L46-L54

Author: jonathanpeppers

src/Controls/src/Build.Tasks/nuget/buildTransitive/netstandard2.0/Microsoft.Maui.Controls.targets

@@ -148,7 +148,7 @@
 		Condition=" '$(DesignTimeBuild)' != 'True' AND '@(MauiXaml)' != ''">
 	    <PropertyGroup>
 		<_MauiXamlCValidateOnly>$(MauiXamlCValidateOnly)</_MauiXamlCValidateOnly>
-		<_MauiXamlCValidateOnly Condition="'$(Configuration)' != 'Release' AND '$(_MauiForceXamlCForDebug)' != 'True'">True</_MauiXamlCValidateOnly>
+		<_MauiXamlCValidateOnly Condition="'$(Configuration)' == 'Debug' AND '$(_MauiForceXamlCForDebug)' != 'True'">True</_MauiXamlCValidateOnly>
 		<_MauiXamlCValidateOnly Condition="'$(BuildingForLiveUnitTesting)' == 'True' ">True</_MauiXamlCValidateOnly>
 	    </PropertyGroup>
 		<XamlCTask

src/Controls/tests/Xaml.UnitTests/MSBuild/MSBuildTests.cs

@@ -72,7 +72,11 @@ static string GetTfm()
 		public void SetUp()
 		{
 			testDirectory = TestContext.CurrentContext.TestDirectory;
-			tempDirectory = IOPath.Combine(testDirectory, "temp", TestContext.CurrentContext.Test.Name);
+			tempDirectory = IOPath.Combine(testDirectory, "temp",
+				TestContext.CurrentContext.Test.Name
+					.Replace('"', '_')
+					.Replace('(', '_')
+					.Replace(')', '_'));
 			intermediateDirectory = IOPath.Combine(tempDirectory, "obj", "Debug", GetTfm());
 			Directory.CreateDirectory(tempDirectory);
 
@@ -259,22 +263,29 @@ public void BuildAProject()
 
 		// Tests the MauiXamlCValidateOnly=True MSBuild property
 		[Test]
-		public void ValidateOnly()
+		public void ValidateOnly([Values("Debug", "Release", "ReleaseProd")] string configuration)
 		{
 			var project = NewProject();
 			project.Add(AddFile("MainPage.xaml", "MauiXaml", Xaml.MainPage));
 			var projectFile = IOPath.Combine(tempDirectory, "test.csproj");
 			project.Save(projectFile);
-			Build(projectFile, additionalArgs: "-p:MauiXamlCValidateOnly=True");
+			intermediateDirectory = IOPath.Combine(tempDirectory, "obj", configuration, GetTfm());
+			Build(projectFile, additionalArgs: $"-c {configuration}");
 
 			var testDll = IOPath.Combine(intermediateDirectory, "test.dll");
 			AssertExists(testDll, nonEmpty: true);
-			using (var assembly = AssemblyDefinition.ReadAssembly(testDll))
+			using var assembly = AssemblyDefinition.ReadAssembly(testDll);
+			var resources = assembly.MainModule.Resources.OfType<EmbeddedResource>().Select(e => e.Name).ToArray();
+			if (configuration == "Debug")
 			{
 				// XAML files should remain as EmbeddedResource
-				var resources = assembly.MainModule.Resources.OfType<EmbeddedResource>().Select(e => e.Name).ToArray();
 				CollectionAssert.Contains(resources, "test.MainPage.xaml");
 			}
+			else
+			{
+				// XAML files should *not* remain as EmbeddedResource
+				CollectionAssert.DoesNotContain(resources, "test.MainPage.xaml");
+			}
 		}
 
 		[Test]