Description of problem:

When creating Host Inventory through ACM/MCE there is information stating "Storage sizes cannot be changed once you configure.".

However I'm unsure why we prohibit changes of these - shouldn't it really depend on capabilities of the storage backend being used?

For an instance:

# oc -n multicluster-engine get pvc
NAME                                          STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS        VOLUMEATTRIBUTESCLASS   AGE
assisted-service                              Bound    pvc-79026b1e-cf3e-4f2e-8002-a86576ee60f8   20Gi       RWO            freenas-iscsi-csi   <unset>                 3d18h
image-service-data-assisted-image-service-0   Bound    pvc-524ce952-03b8-410d-ba7c-0b778457d4fd   40Gi       RWO            freenas-iscsi-csi   <unset>                 3d18h
postgres                                      Bound    pvc-9f61e928-1638-4fac-aeee-16b33c51cff1   5Gi        RWO            freenas-iscsi-csi   <unset>                 3d18h

I could easily expand image-service-data-assisted-image-service-0 PVC since initially allocated disk space was not sufficient. However I had to do it directly with PVC. 

If we don't want to allow users to use this WebUI interface to make such changes, we should at least provide information that it can be potentially done (when storage backend allows) directly with PVC. Otherwise there is an impression that once set, the size cannot be changed. 

At the same time, we provide advise to the user: "(...) Recommended is XYZGi or more. The value cannot be updated later." This isn't clear - how end user can know if XYZ is enough? If not, what is behind "more" in this case? This is especially suboptimal approach when we say that "The value cannot be updated later.".