Update dependencies from https://github.com/dotnet/corefx build 20200427.1 (#21263)

- System.Net.Http.Json: 3.2.0-rc1.20224.1 -> 3.2.0

Co-authored-by: dotnet-maestro[bot] <dotnet-maestro[bot]@users.noreply.github.com>

Author: dotnet-maestro[bot]

NuGet.config

@@ -3,6 +3,7 @@
   <packageSources>
     <clear />
     <!--Begin: Package sources managed by Dependency Flow automation. Do not edit the sources below.-->
+    <add key="darc-pub-dotnet-corefx-66409e3" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/darc-pub-dotnet-corefx-66409e39/nuget/v3/index.json" />
     <add key="darc-pub-dotnet-blazor-cdc7d4b" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/darc-pub-dotnet-blazor-cdc7d4bd/nuget/v3/index.json" />
     <!--End: Package sources managed by Dependency Flow automation. Do not edit the sources above.-->
     <add key="dotnet-tools" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-tools/nuget/v3/index.json" />

eng/Version.Details.xml

@@ -13,9 +13,9 @@
       <Uri>https://github.com/dotnet/blazor</Uri>
       <Sha>cdc7d4bdb60bf7b5b29d88d63b3561ea63ac7c58</Sha>
     </Dependency>
-    <Dependency Name="System.Net.Http.Json" Version="3.2.0-rc1.20224.1">
+    <Dependency Name="System.Net.Http.Json" Version="3.2.0">
       <Uri>https://github.com/dotnet/corefx</Uri>
-      <Sha>4b30bea794790b157c787f5ee382dc6defe1dcec</Sha>
+      <Sha>66409e392d64ed96e5d3a5fda712d9baf51196ed</Sha>
     </Dependency>
   </ProductDependencies>
   <ToolsetDependencies>

eng/Versions.props

@@ -90,7 +90,7 @@
     <SystemServiceProcessServiceControllerPackageVersion>4.7.0</SystemServiceProcessServiceControllerPackageVersion>
     <SystemTextEncodingsWebPackageVersion>4.7.0</SystemTextEncodingsWebPackageVersion>
     <SystemTextJsonPackageVersion>4.7.1</SystemTextJsonPackageVersion>
-    <SystemNetHttpJsonPackageVersion>3.2.0-rc1.20224.1</SystemNetHttpJsonPackageVersion>
+    <SystemNetHttpJsonPackageVersion>3.2.0</SystemNetHttpJsonPackageVersion>
     <SystemThreadingChannelsPackageVersion>4.7.0</SystemThreadingChannelsPackageVersion>
     <SystemWindowsExtensionsPackageVersion>4.7.0</SystemWindowsExtensionsPackageVersion>
     <!-- Only listed explicitly to workaround https://github.com/dotnet/cli/issues/10528 -->