EUS not suported in extras - update rhui doc too

Author: asinn826

articles/virtual-machines/linux/update-infrastructure-redhat.md

@@ -44,6 +44,9 @@ Information on Red Hat support policies for all versions of RHEL can be found on
 ## RHEL EUS and version-locking RHEL VMs
 Some customers may want to lock their RHEL VMs to a certain RHEL minor release. You can version-lock your RHEL VM to a specific minor version by updating the repositories to point to the Extended Update Support repositories. You can also undo the EUS version-locking operation.
 
+>[!NOTE]
+> EUS is not supported on RHEL Extras. This means that if you are installing a package that is usually available from the RHEL Extras channel, you will not be able to do so while on EUS. The Red Hat Extras Product Life Cycle is detailed [here](https://access.redhat.com/support/policy/updates/extras/).
+
 At the time of this writing, EUS support has ended for RHEL <= 7.3. See the "Red Hat Enterprise Linux Longer Support Add-Ons" section in the [Red Hat documentation](https://access.redhat.com/support/policy/updates/errata/) for more details.
 * RHEL 7.4 EUS support ends August 31, 2019
 * RHEL 7.5 EUS support ends April 30, 2020