[master] Update dependencies from dotnet/corefx (dotnet#24521)

* Update dependencies from https://github.com/dotnet/corefx build 20190513.9

- Microsoft.NETCore.Platforms - 3.0.0-preview6.19263.9
- Microsoft.Private.CoreFx.NETCoreApp - 4.6.0-preview6.19263.9

* Add dependency flow for Microsoft.Bcl.AsyncInterfaces

Author: dotnet-maestro[bot]

eng/Version.Details.xml

@@ -15,13 +15,17 @@
       <Uri>https://github.com/dotnet/arcade</Uri>
       <Sha>a7a250e9c13147134543c35fef2fb81f19592edf</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.Private.CoreFx.NETCoreApp" Version="4.6.0-preview6.19259.1">
+    <Dependency Name="Microsoft.Private.CoreFx.NETCoreApp" Version="4.6.0-preview6.19263.9">
       <Uri>https://github.com/dotnet/corefx</Uri>
-      <Sha>f7cd353ab8b08ff45d45985851505e5f8f19f9ac</Sha>
+      <Sha>f5be0283c5e00dd823a41f671f9c9a41170f0a85</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.NETCore.Platforms" Version="3.0.0-preview6.19259.1">
+    <Dependency Name="Microsoft.NETCore.Platforms" Version="3.0.0-preview6.19263.9">
       <Uri>https://github.com/dotnet/corefx</Uri>
-      <Sha>f7cd353ab8b08ff45d45985851505e5f8f19f9ac</Sha>
+      <Sha>f5be0283c5e00dd823a41f671f9c9a41170f0a85</Sha>
+    </Dependency>
+    <Dependency Name="Microsoft.Bcl.AsyncInterfaces" Version="1.0.0-preview6.19263.9">
+      <Uri>https://github.com/dotnet/corefx</Uri>
+      <Sha>f5be0283c5e00dd823a41f671f9c9a41170f0a85</Sha>
     </Dependency>
     <Dependency Name="Microsoft.NETCore.App" Version="3.0.0-preview5-27620-01">
       <Uri>https://github.com/dotnet/core-setup</Uri>

eng/Versions.props

@@ -9,9 +9,9 @@
     <UsingToolNetFrameworkReferenceAssemblies>true</UsingToolNetFrameworkReferenceAssemblies>
     <MicrosoftDotNetXUnitConsoleRunnerVersion>2.5.1-beta.19179.4</MicrosoftDotNetXUnitConsoleRunnerVersion>
     <MicrosoftNetFrameworkReferenceAssembliesVersion>1.0.0-alpha-004</MicrosoftNetFrameworkReferenceAssembliesVersion>
-    <MicrosoftPrivateCoreFxNETCoreAppVersion>4.6.0-preview6.19259.1</MicrosoftPrivateCoreFxNETCoreAppVersion>
-    <MicrosoftNETCorePlatformsVersion>3.0.0-preview6.19259.1</MicrosoftNETCorePlatformsVersion>
-    <MicrosoftBclAsyncInterfacesVersion>1.0.0-preview6.19257.8</MicrosoftBclAsyncInterfacesVersion>
+    <MicrosoftPrivateCoreFxNETCoreAppVersion>4.6.0-preview6.19263.9</MicrosoftPrivateCoreFxNETCoreAppVersion>
+    <MicrosoftNETCorePlatformsVersion>3.0.0-preview6.19263.9</MicrosoftNETCorePlatformsVersion>
+    <MicrosoftBclAsyncInterfacesVersion>1.0.0-preview6.19263.9</MicrosoftBclAsyncInterfacesVersion>
     <MicrosoftNETCoreAppVersion>3.0.0-preview5-27620-01</MicrosoftNETCoreAppVersion>
     <MicrosoftDotNetBuildTasksFeedVersion>2.2.0-beta.19229.8</MicrosoftDotNetBuildTasksFeedVersion>
     <optimizationIBCCoreCLRVersion>99.99.99-master-20190510.1</optimizationIBCCoreCLRVersion>