Merge in 'release/6.0' changes

eng/Versions.props

 <Project>
   <PropertyGroup>
     <!-- The .NET product branding version -->
-    <ProductVersion>6.0.19</ProductVersion>
+    <ProductVersion>6.0.20</ProductVersion>
     <!-- File version numbers -->
     <MajorVersion>6</MajorVersion>
     <MinorVersion>0</MinorVersion>
-    <PatchVersion>19</PatchVersion>
+    <PatchVersion>20</PatchVersion>
     <SdkBandVersion>6.0.400</SdkBandVersion>
     <PreReleaseVersionLabel>servicing</PreReleaseVersionLabel>
     <PreReleaseVersionIteration>