downgrade netwonsoft dependency to avoid a memory leak in v12 (#249)

Author: leoek

windows/ReactNativePSPDFKit/ReactNativePSPDFKit/ReactNativePSPDFKit.csproj

@@ -131,7 +131,7 @@
       <Version>2.0.1</Version>
     </PackageReference>
     <PackageReference Include="Newtonsoft.Json">
-      <Version>12.0.2</Version>
+      <Version>11.0.2</Version>
     </PackageReference>
   </ItemGroup>
   <ItemGroup>