fix: use cluster admin instead of admin (eclipse-che#2953)

* fix: use cluster admin instead of admin

Signed-off-by: Valeriy Svydenko <vsvydenk@redhat.com>

* Update modules/administration-guide/examples/snip_che-deploy-open-vsx-using-oc.adoc

Co-authored-by: Jana Vrbkova <jvrbkova@redhat.com>

* Update modules/administration-guide/pages/running-the-open-vsx-on-premises.adoc

Co-authored-by: Jana Vrbkova <jvrbkova@redhat.com>

* Update modules/administration-guide/pages/running-the-open-vsx-on-premises.adoc

Co-authored-by: Ilya Buziuk <ibuziuk@redhat.com>

---------

Signed-off-by: Valeriy Svydenko <vsvydenk@redhat.com>
Co-authored-by: Jana Vrbkova <jvrbkova@redhat.com>
Co-authored-by: Ilya Buziuk <ibuziuk@redhat.com>

Author: 3 people

modules/administration-guide/examples/snip_che-deploy-open-vsx-using-oc.adoc

@@ -1,6 +1,6 @@
 * Installed `oc` and git tools.
 * Installed Podman.
-* Log in to the OpenShift cluster where a {prod-short} is deployed as an administrator.
+* Log in to the OpenShift cluster where the {prod-short} is deployed as a cluster administrator.
 +
 [TIP]
 ====

modules/administration-guide/pages/running-the-open-vsx-on-premises.adoc

@@ -13,7 +13,7 @@ Follow the instructions below to deploy and configure an on-premises Eclipse Ope
 
 .Prerequisites
 
-* Be logged in to a {prod-short} as an administrator.
+* Be logged in as a cluster administrator.
 
 .Procedure