Use preview 2 for aliasing opt-in (#7121)

* use preview 2 for opt-in

* use static

Author: nkolev92

src/NuGet.Core/NuGet.Commands/RestoreCommand/RestoreCommand.cs

@@ -1971,6 +1971,9 @@ private static async Task<IList<CompatibilityCheckResult>> VerifyCompatibilityAs
             return (success, graphs);
         }
 
+        private static NuGetVersion Version_11_WithAliasSupport = NuGetVersion.Parse("11.0.100-preview.2.26104");
+        private static NuGetVersion Version_10_WithAliasSupport = NuGetVersion.Parse("10.0.300-preview.1");
+
         private static bool DoesProjectToolsetSupportsDuplicateFrameworks(PackageSpec project)
         {
             if (project.RestoreMetadata.UsingMicrosoftNETSdk &&
@@ -1990,7 +1993,7 @@ private static bool DoesProjectToolsetSupportsDuplicateFrameworks(PackageSpec pr
                         && project.RestoreSettings.SdkVersion.Minor == 0
                         && project.RestoreSettings.SdkVersion.Patch == 300)
                     {
-                        if (project.RestoreSettings.SdkVersion < NuGetVersion.Parse("10.0.300-preview.1"))
+                        if (project.RestoreSettings.SdkVersion < Version_10_WithAliasSupport)
                         {
                             return false;
                         }
@@ -1999,7 +2002,7 @@ private static bool DoesProjectToolsetSupportsDuplicateFrameworks(PackageSpec pr
                         && project.RestoreSettings.SdkVersion.Minor == 0
                         && project.RestoreSettings.SdkVersion.Patch == 100)
                     {
-                        if (project.RestoreSettings.SdkVersion < NuGetVersion.Parse("11.0.100-preview.1.26104"))
+                        if (project.RestoreSettings.SdkVersion < Version_11_WithAliasSupport)
                         {
                             return false;
                         }

test/NuGet.Core.FuncTests/NuGet.Commands.FuncTest/RestoreCommand_Aliases.cs

@@ -412,7 +412,7 @@ public async Task RestoreCommand_WithAliasesOfSameFramework_MultipleProjectRefer
         [Theory]
         [InlineData("10.0.200", "10.0.300")]
         [InlineData("10.0.300", "10.0.300-preview.0.12345")]
-        [InlineData("11.0.100", "11.0.100-preview.1.26103")]
+        [InlineData("11.0.100", "11.0.100-preview.2.26103")]
         public async Task RestoreCommand_WithAliasesOfSameFramework_AndIncompatibleSDKAnalysisLevelAndSDKVersionCombinations_FailsWithNU1018(string sdkAnalysisLevel, string sdkVersion)
         {
             using var pathContext = new SimpleTestPathContext();
@@ -429,7 +429,7 @@ public async Task RestoreCommand_WithAliasesOfSameFramework_AndIncompatibleSDKAn
         [InlineData("10.0.300", "10.0.400")]
         [InlineData("10.0.300", null)] // Null value means we let it be.
         [InlineData("10.0.300", "10.0.300-preview.1.12345")] // This is a dummy value that'll need to be updated once we have a real one.
-        [InlineData("11.0.100", "11.0.100-preview.1.26104")]
+        [InlineData("11.0.100", "11.0.100-preview.2.26104")]
         [InlineData("11.0.100", "11.0.100")]
         [InlineData("11.0.100", "11.0.101")]
         public async Task RestoreCommand_WithAliasesOfSameFramework_AndValidSDKAnalysisLevelAndSDKVersionCombinations_Succeeds(string sdkAnalysisLevel, string sdkVersion)