[release/6.0] Update IntelliSense package (#60621)

* Update IntelliSense package

* Fixed package version

Co-authored-by: carlossanlop <carlossanlop@users.noreply.github.com>
Co-authored-by: carlossanlop <1175054+carlossanlop@users.noreply.github.com>

Author: github-actions[bot]

eng/Versions.props

@@ -165,7 +165,7 @@
     <FsCheckVersion>2.14.3</FsCheckVersion>
     <SdkVersionForWorkloadTesting>6.0.100-rtm.21480.21</SdkVersionForWorkloadTesting>
     <!-- Docs -->
-    <MicrosoftPrivateIntellisenseVersion>6.0.0-preview-20210916.1</MicrosoftPrivateIntellisenseVersion>
+    <MicrosoftPrivateIntellisenseVersion>6.0.0-preview-20211019.1</MicrosoftPrivateIntellisenseVersion>
     <!-- ILLink -->
     <MicrosoftNETILLinkTasksVersion>6.0.100-1.21459.1</MicrosoftNETILLinkTasksVersion>
     <MicrosoftNETILLinkAnalyzerPackageVersion>$(MicrosoftNETILLinkTasksVersion)</MicrosoftNETILLinkAnalyzerPackageVersion>