[cloud-admin-guide] Storage concepts update

In cloud admin guide, storage encrytion is missing in the
comparion of storage types. An indicaion of the availability
of ephemeral and block storage encryption could be addressed
by adding a brief row releating to this in Table 1.2

Closes-Bug: #1473165
Change-Id: Ib89b716cdc89377f049935dd87e56cacf11762d0

doc/common-rst/get_started_storage_concepts.rst

@@ -24,6 +24,9 @@ The OpenStack stack uses the following storage types:
    * - Implemented as a filesystem underlying OpenStack Compute
      - Mounted via OpenStack Block Storage controlled protocol (for example, iSCSI)
      - REST API
+   * - Encryption is available
+     - Encryption is available
+     - Work in progress - expected for the Mitaka release
    * - Administrator configures size setting, based on flavors
      - Sizings based on need
      - Easily scalable for future growth

doc/common/section_storage-concepts.xml

@@ -46,6 +46,11 @@
           (for example, iSCSI)</td>
         <td>REST API</td>
       </tr>
+      <tr>
+        <td>Encryption is available</td>
+        <td>Encryption is available</td>
+        <td>Work in progress - Expected for the Mitaka release</td>
+      </tr>
       <tr>
         <td>Administrator configures size setting, based on
           flavors</td>