Update storage technology for OpenShift Logging

Versions:
4.10, 4.11, 4.12

OpenShift Elasticsearch operator is deprecated and is going to be completely replaced by Loki. As per the documentation[1], block storage is recommended but this is partial information as per current situation. Loki uses Object Storage only. So, the table mentioned the documentation needs to be updated for Loki.

And same needs to be corrected in this documentation[2] as well. Logging section should look like:

• The preferred storage technology is block storage for OpenShift Elasticsearch operator.
• Loki Operator uses object storage only.

[1] https://docs.openshift.com/container-platform/4.12/scalability_and_performance/optimizing-storage.html#recommended-configurable-storage-technology_persistent-storage
[2] https://docs.openshift.com/container-platform/4.12/scalability_and_performance/optimizing-storage.html#specific-application-storage-recommendations