Bump LibZipSharp to 2.0.3 (#151)

Bump LibZipSharp to 2.0.3

Context: dotnet/android-libzipsharp#104

Changes

- Don't rewind the temporary stream on write to the main one

dotnet/android-libzipsharp@2.0.2...2.0.3

Author: dellis1972

src/Microsoft.Android.Build.BaseTasks/MSBuildReferences.projitems

@@ -5,7 +5,7 @@
   <!--Import this file in projects needing to reference Microsoft.Build.*.dll -->
   <PropertyGroup>
     <MSBuildPackageReferenceVersion>16.10.0</MSBuildPackageReferenceVersion>
-    <LibZipSharpVersion Condition=" '$(LibZipSharpVersion)' == '' " >2.0.2</LibZipSharpVersion>
+    <LibZipSharpVersion Condition=" '$(LibZipSharpVersion)' == '' " >2.0.3</LibZipSharpVersion>
     <MonoUnixVersion>7.0.0-final.1.21369.2</MonoUnixVersion>
   </PropertyGroup>