Allow overrides for Restore properties

- Allow overrides for properties such as
  1. `ManagePackageVersionsCentrally`
  2. `RestoreEnableGlobalPackageReference`
  3. `DisableCheckingDuplicatePackage(Download|Reference|Version)s`

Sources/NuGet.Build.Sdk/Core/NuGet.Restore.targets

@@ -184,6 +184,7 @@
 		<!-- Design-Time builds should not produce a build error. So, we need to ensure that we continue on error -->
 		<PropertyGroup>
 			<CollectPackageReferencesContinueOnError>$([MSBuild]::ValueOrDefault($(ContinueOnError), 'false'))</CollectPackageReferencesContinueOnError>
+			<DisableCheckingDuplicatePackageReferences>$([MSBuild]::ValueOrDefault($(DisableCheckingDuplicateNuGetItems), $(DisableCheckingDuplicatePackageReferences)))</DisableCheckingDuplicatePackageReferences>
 		</PropertyGroup>
 
 		<CheckForDuplicateNuGetItemsTask
@@ -195,7 +196,7 @@
 			TreatWarningsAsErrors="$(TreatWarningsAsErrors)"
 			MSBuildProjectFullPath="$(MSBuildProjectFullPath)"
 			ContinueOnError="$(CollectPackageReferencesContinueOnError)"
-			Condition="'$(DisableCheckingDuplicateNuGetItems)' != 'true'">
+			Condition="'$(DisableCheckingDuplicatePackageReferences)' != 'true'">
 			<Output TaskParameter="DeduplicatedItems" ItemName="DeduplicatedPackageReference"/>
 		</CheckForDuplicateNuGetItemsTask>
 
@@ -220,6 +221,7 @@
 		<!-- Design-Time builds should not produce a build error. So, we need to ensure that we continue on error -->
 		<PropertyGroup>
 			<CollectCentralPackageVersionsContinueOnError>$([MSBuild]::ValueOrDefault($(ContinueOnError), 'false'))</CollectCentralPackageVersionsContinueOnError>
+			<DisableCheckingDuplicatePackageVersions>$([MSBuild]::ValueOrDefault($(DisableCheckingDuplicateNuGetItems), $(DisableCheckingDuplicatePackageVersions)))</DisableCheckingDuplicatePackageVersions>
 		</PropertyGroup>
 
 		<CheckForDuplicateNuGetItemsTask
@@ -231,7 +233,7 @@
 			TreatWarningsAsErrors="$(TreatWarningsAsErrors)"
 			MSBuildProjectFullPath="$(MSBuildProjectFullPath)"
 			ContinueOnError="$(CollectCentralPackageVersionsContinueOnError)"
-			Condition="'$(DisableCheckingDuplicateNuGetItems)' != 'true'">
+			Condition="'$(DisableCheckingDuplicatePackageVersions)' != 'true'">
 			<Output TaskParameter="DeduplicatedItems" ItemName="DeduplicatedPackageVersion"/>
 		</CheckForDuplicateNuGetItemsTask>
 
@@ -256,6 +258,7 @@
 		<!-- Design-Time builds should not produce a build error. So, we need to ensure that we continue on error -->
 		<PropertyGroup>
 			<CollectPackageDownloadsContinueOnError>$([MSBuild]::ValueOrDefault($(ContinueOnError), 'false'))</CollectPackageDownloadsContinueOnError>
+			<DisableCheckingDuplicatePackageDownloads>$([MSBuild]::ValueOrDefault($(DisableCheckingDuplicateNuGetItems), $(DisableCheckingDuplicatePackageDownloads)))</DisableCheckingDuplicatePackageDownloads>
 		</PropertyGroup>
 
 		<CheckForDuplicateNuGetItemsTask
@@ -267,7 +270,7 @@
 			TreatWarningsAsErrors="$(TreatWarningsAsErrors)"
 			MSBuildProjectFullPath="$(MSBuildProjectFullPath)"
 			ContinueOnError="$(CollectPackageDownloadsContinueOnError)"
-			Condition="'$(DisableCheckingDuplicateNuGetItems)' != 'true'">
+			Condition="'$(DisableCheckingDuplicatePackageDownloads)' != 'true'">
 			<Output TaskParameter="DeduplicatedItems" ItemName="DeduplicatedPackageDownload"/>
 		</CheckForDuplicateNuGetItemsTask>
 

Sources/NuGet.Build.Sdk/Extensions/Directory.Packages.props

@@ -45,9 +45,9 @@
 	<Import Project="$(DirectoryPackagesProps)" Condition="Exists('$(DirectoryPackagesProps)')"/>
 
 	<PropertyGroup Condition="Exists('$(DirectoryPackagesProps)')">
-		<ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
 		<CentralPackageVersionsFileImported>true</CentralPackageVersionsFileImported>
-		<RestoreEnableGlobalPackageReference>true</RestoreEnableGlobalPackageReference>
+		<ManagePackageVersionsCentrally Condition="'$(ManagePackageVersionsCentrally)' == ''">true</ManagePackageVersionsCentrally>
+		<RestoreEnableGlobalPackageReference Condition="'$(RestoreEnableGlobalPackageReference)' == ''">true</RestoreEnableGlobalPackageReference>
 	</PropertyGroup>
 
 </Project>