Update dependencies from https://github.com/dotnet/corefx build 20191023.1 (dotnet#27385)

- Microsoft.NETCore.Platforms - 5.0.0-alpha1.19523.1
- Microsoft.Private.CoreFx.NETCoreApp - 5.0.0-alpha1.19523.1

Author: dotnet-maestro[bot]

eng/Version.Details.xml

@@ -19,13 +19,13 @@
       <Uri>https://github.com/dotnet/arcade</Uri>
       <Sha>7b731032220c21a3ed0021c72757b1f3122579b2</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.Private.CoreFx.NETCoreApp" Version="5.0.0-alpha1.19521.4">
+    <Dependency Name="Microsoft.Private.CoreFx.NETCoreApp" Version="5.0.0-alpha1.19523.1">
       <Uri>https://github.com/dotnet/corefx</Uri>
-      <Sha>46299619e290936c495264162ede68354ced5b18</Sha>
+      <Sha>b8cb521e83456bd81dc314c0625d6236d7955bd9</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.NETCore.Platforms" Version="5.0.0-alpha1.19521.4">
+    <Dependency Name="Microsoft.NETCore.Platforms" Version="5.0.0-alpha1.19523.1">
       <Uri>https://github.com/dotnet/corefx</Uri>
-      <Sha>46299619e290936c495264162ede68354ced5b18</Sha>
+      <Sha>b8cb521e83456bd81dc314c0625d6236d7955bd9</Sha>
     </Dependency>
     <Dependency Name="Microsoft.NETCore.App" Version="5.0.0-alpha1.19510.2">
       <Uri>https://github.com/dotnet/core-setup</Uri>

eng/Versions.props

@@ -20,8 +20,8 @@
     <MicrosoftDotNetXUnitConsoleRunnerVersion>2.5.1-beta.19278.1</MicrosoftDotNetXUnitConsoleRunnerVersion>
     <MicrosoftDotNetVersionToolsTasksVersion>1.0.0-beta.19463.3</MicrosoftDotNetVersionToolsTasksVersion>
     <!-- corefx -->
-    <MicrosoftPrivateCoreFxNETCoreAppPackageVersion>5.0.0-alpha1.19521.4</MicrosoftPrivateCoreFxNETCoreAppPackageVersion>
-    <MicrosoftNETCorePlatformsVersion>5.0.0-alpha1.19521.4</MicrosoftNETCorePlatformsVersion>
+    <MicrosoftPrivateCoreFxNETCoreAppPackageVersion>5.0.0-alpha1.19523.1</MicrosoftPrivateCoreFxNETCoreAppPackageVersion>
+    <MicrosoftNETCorePlatformsVersion>5.0.0-alpha1.19523.1</MicrosoftNETCorePlatformsVersion>
     <MicrosoftBclAsyncInterfacesVersion>1.0.0-preview7.19326.2</MicrosoftBclAsyncInterfacesVersion>
     <!-- core-setup -->
     <MicrosoftNETCoreAppVersion>5.0.0-alpha1.19510.2</MicrosoftNETCoreAppVersion>