System.Speech: Use intellisense xml from dotnet-api-docs (#111983)

Author: carlossanlop

src/libraries/System.Speech/src/System.Speech.csproj

@@ -3,6 +3,7 @@
   <PropertyGroup>
     <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent);$(NetCoreAppMinimum)-windows;$(NetCoreAppMinimum);netstandard2.0</TargetFrameworks>
     <TargetFrameworks Condition="'$(NetCoreAppPrevious)' != ''">$(TargetFrameworks);$(NetCoreAppPrevious)-windows;$(NetCoreAppPrevious)</TargetFrameworks>
+    <UseCompilerGeneratedDocXmlFile>false</UseCompilerGeneratedDocXmlFile>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <!-- CS0649: uninitialized interop type fields -->
     <!-- SA1129: https://github.com/DotNetAnalyzers/StyleCopAnalyzers/issues/3277 -->