Update dependencies from...

Update dependencies from https://dev.azure.com/dnceng/internal/_git/dotnet-wpf-int build 20190816.7 (#1656)

- Microsoft.DotNet.Wpf.DncEng - 4.8.0-preview9.19416.7

eng/Version.Details.xml

@@ -75,9 +75,9 @@
       <Uri>https://github.com/dotnet/corefx</Uri>
       <Sha>b82d2bc44424c8a99a1f0fc13202bdfd43e6f9f5</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.DotNet.Wpf.DncEng" Version="4.8.0-preview9.19416.4">
+    <Dependency Name="Microsoft.DotNet.Wpf.DncEng" Version="4.8.0-preview9.19416.7">
       <Uri>https://dev.azure.com/dnceng/internal/_git/dotnet-wpf-int</Uri>
-      <Sha>1d7c163f73ab4451a9614ff2a6294643c3575dbe</Sha>
+      <Sha>9dbf98944d032f91760e92882c80859cbf45b847</Sha>
     </Dependency>
     <Dependency Name="System.IO.Packaging" Version="4.6.0-preview9.19409.17" CoherentParentDependency="Microsoft.NETCore.App">
       <Uri>https://github.com/dotnet/corefx</Uri>

eng/Versions.props

@@ -112,6 +112,6 @@
       It is worth reiterating that this package *should not* be consumed to build the product.
   -->
   <PropertyGroup>
-    <MicrosoftDotNetWpfDncEngVersion>4.8.0-preview9.19416.4</MicrosoftDotNetWpfDncEngVersion>
+    <MicrosoftDotNetWpfDncEngVersion>4.8.0-preview9.19416.7</MicrosoftDotNetWpfDncEngVersion>
   </PropertyGroup>
 </Project>