Update supported configurations topic for OSSM 2.2

https://docs.openshift.com/container-platform/4.10/service_mesh/v2x/preparing-ossm-installation.html#ossm-supported-configurations_preparing-ossm-installation

OK, the history on this one is a little bit convoluted.

We updated the supported configurations topic as part of OSSMDOC-557.  https://github.com/openshift/openshift-docs/pull/44836/files

Red Hat {product-title} version 4.x.
 
 Changed to

Red Hat {product-title} version 4.9 or later.

Then someone filed an issue against the changes,  https://github.com/openshift/openshift-docs/issues/45352

What needs fixing?

• Red Hat OpenShift Container Platform version 4.9 or later.
  This should be wrong, as current OSSM release should be supported on EUS OCP 4.8, 4.6 as well as current OCP releases.

So we changed it again in this PR  https://github.com/openshift/openshift-docs/pull/45442

version 4.6 or later.

And now, once we release OSSM 2.2, we need to update this again, as we will no longer be supporting 4.6, 4.6EUS, 4.7, or 4.8.  (See https://access.redhat.com/support/policy/updates/openshift#dates)

 TO DO

Update modules/ossm-supported-configurations.adoc to read "Red Hat OpenShift Container Platform version 4.9 or later."

ALSO

Line 51 remove the word Kiali observability console.