Update dependencies from https://github.com/dotnet/winforms build 20190823.4 (#1715)

- Microsoft.Private.Winforms - 4.8.0-rc1.19423.4

Dependency coherency updates

- Microsoft.NETCore.App - 3.0.0-rc1-19423-11 (parent: Microsoft.Private.Winforms)

eng/Version.Details.xml

 <?xml version="1.0" encoding="utf-8"?>
 <Dependencies>
   <ProductDependencies>
-    <Dependency Name="Microsoft.Private.Winforms" Version="4.8.0-rc1.19423.3">
+    <Dependency Name="Microsoft.Private.Winforms" Version="4.8.0-rc1.19423.4">
       <Uri>https://github.com/dotnet/winforms</Uri>
-      <Sha>339b8d57f0173c8fff2f3ddb6f0316470341aaea</Sha>
+      <Sha>ff7015f045cb1daf43ccd6106c28a5d306ee1581</Sha>
     </Dependency>
   </ProductDependencies>
   <ToolsetDependencies>
@@ -59,9 +59,9 @@
       <Uri>https://github.com/dotnet/corefx</Uri>
       <Sha>d341fd37dcb2c22e382adccdc06770cf8f160577</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.NETCore.App" Version="3.0.0-rc1-19422-14" CoherentParentDependency="Microsoft.Private.Winforms">
+    <Dependency Name="Microsoft.NETCore.App" Version="3.0.0-rc1-19423-11" CoherentParentDependency="Microsoft.Private.Winforms">
       <Uri>https://github.com/dotnet/core-setup</Uri>
-      <Sha>24da14999a8c6d711972b72812ec0c0df82be0c9</Sha>
+      <Sha>abecfcd748e6b8850e1111184bf34c93e9277f90</Sha>
     </Dependency>
     <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="1.0.0-beta.19411.1">
       <Uri>https://github.com/dotnet/arcade</Uri>

eng/Versions.props

@@ -8,7 +8,7 @@
   </PropertyGroup>
   <!-- NuGet Package Versions -->
   <PropertyGroup>
-    <MicrosoftPrivateWinformsVersion>4.8.0-rc1.19423.3</MicrosoftPrivateWinformsVersion>
+    <MicrosoftPrivateWinformsVersion>4.8.0-rc1.19423.4</MicrosoftPrivateWinformsVersion>
   </PropertyGroup>
   <!-- Packages that come from https://github.com/dotnet/coreclr -->
   <PropertyGroup>
@@ -18,7 +18,7 @@
   </PropertyGroup>
   <!-- Packages that come from https://github.com/dotnet/core-setup -->
   <PropertyGroup>
-    <MicrosoftNETCoreAppVersion>3.0.0-rc1-19422-14</MicrosoftNETCoreAppVersion>
+    <MicrosoftNETCoreAppVersion>3.0.0-rc1-19423-11</MicrosoftNETCoreAppVersion>
     <MicrosoftNETCorePlatformsVersion>3.0.0-rc1.19420.10</MicrosoftNETCorePlatformsVersion>
     <SystemDrawingCommonVersion>4.6.0-rc1.19420.10</SystemDrawingCommonVersion>
     <SystemDirectoryServicesVersion>4.6.0-rc1.19420.10</SystemDirectoryServicesVersion>