Follow Deterministic configuration when using NuGetPack

This should be a no-op because PackageBuilder currently ignores the
setting. However, if/when PackageBuilder starts following it, we should
start getting deterministic builds too.

Also renamed the Task invocation in the targets file to make the casing
of the task definition. It doesn't matter because MSBuild is
case-insensitive, but it's easier to search for.

Author: omajid

src/Microsoft.DotNet.Build.Tasks.Packaging/src/NuGetPack.cs

@@ -132,6 +132,12 @@ public string PackedPackageNamePrefix
             set;
         }
 
+        public bool Deterministic
+        {
+            get;
+            set;
+        }
+
         public override bool Execute()
         {
             if (Nuspecs == null || Nuspecs.Length == 0)
@@ -254,7 +260,7 @@ public void Pack(string nuspecPath, string nupkgPath, Manifest manifest, bool pa
             bool creatingSymbolsPackage = packSymbols && (Path.GetExtension(nupkgPath) == _symbolsPackageExtension);
             try
             {
-                PackageBuilder builder = new PackageBuilder();
+                PackageBuilder builder = new PackageBuilder(deterministic: Deterministic);
 
                 string baseDirectoryPath = (string.IsNullOrEmpty(BaseDirectory)) ? Path.GetDirectoryName(nuspecPath) : BaseDirectory;
                 builder.Populate(manifest.Metadata);

src/Microsoft.DotNet.Build.Tasks.Packaging/src/build/Packaging.targets

@@ -1271,7 +1271,7 @@
 
     <Message Condition="'$(_SkipCreatePackage)' == 'true'" Text="Skipping package creation for $(NuSpecPath) because the following files do not exist: @(_missingFiles)" />
 
-    <NugetPack Nuspecs="$(NuSpecPath)"
+    <NuGetPack Nuspecs="$(NuSpecPath)"
                OutputDirectory="$(PackageOutputPath)"
                ExcludeEmptyDirectories="true"
                CreateSymbolPackage="true"
@@ -1282,6 +1282,7 @@
                AdditionalLibPackageExcludes="@(AdditionalLibPackageExcludes)"
                AdditionalSymbolPackageExcludes="@(AdditionalSymbolPackageExcludes)"
                PackedPackageNamePrefix="$(PackedPackageNamePrefix)"
+               Deterministic="$(Deterministic)"
                Condition="'$(_SkipCreatePackage)' != 'true'"/>
 
     <!-- Create a marker that records the path to the generated package -->