Description of problem:
Tiering related information is not displayed in gluster volume info xml output. It would be good if the information is displayed in xml output for the automation purpose.

Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
1. Create a volume.
2. Attach tier bricks.
3. Execute "gluster volume info --xml"

Actual results:
Tiering related information is not displayed in gluster volume info xml output

Expected results:
Tiering related information should be displayed in gluster volume info xml output

Additional info:

[root@node31 ~]# gluster volume info
 
Volume Name: testvol
Type: Tier
Volume ID: 496dfa0d-a370-4dd9-84b5-4048e91aef71
Status: Started
Number of Bricks: 3
Transport-type: tcp
Hot Tier :
Hot Tier Type : Distribute
Number of Bricks: 2
Brick1: 10.70.46.51:/bricks/brick0/testvol_tier1
Brick2: 10.70.47.76:/bricks/brick1/testvol_tier0
Cold Tier:
Cold Tier Type : Distribute
Number of Bricks: 1
Brick3: 10.70.47.76:/bricks/brick0/testvol_brick0
Options Reconfigured:
performance.readdir-ahead: on
[root@node31 ~]# 
[root@node31 ~]# gluster volume info --xml
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<cliOutput>
  <opRet>0</opRet>
  <opErrno>0</opErrno>
  <opErrstr/>
  <volInfo>
    <volumes>
      <volume>
        <name>testvol</name>
        <id>496dfa0d-a370-4dd9-84b5-4048e91aef71</id>
        <status>1</status>
        <statusStr>Started</statusStr>
        <brickCount>3</brickCount>
        <distCount>1</distCount>
        <stripeCount>1</stripeCount>
        <replicaCount>1</replicaCount>
        <disperseCount>0</disperseCount>
        <redundancyCount>0</redundancyCount>
        <type>5</type>
        <typeStr>Tier</typeStr>
        <transport>0</transport>
        <xlators/>
        <bricks>
          <brick uuid="9d77138d-ce50-4fdd-9dad-6c4efbd391e7">10.70.46.51:/bricks/brick0/testvol_tier1<name>10.70.46.51:/bricks/brick0/testvol_tier1</name><hostUuid>9d77138d-ce50-4fdd-9dad-6c4efbd391e7</hostUuid></brick>
          <brick uuid="261b213b-a9f6-4fb6-8313-11e7eba47258">10.70.47.76:/bricks/brick1/testvol_tier0<name>10.70.47.76:/bricks/brick1/testvol_tier0</name><hostUuid>261b213b-a9f6-4fb6-8313-11e7eba47258</hostUuid></brick>
          <brick uuid="261b213b-a9f6-4fb6-8313-11e7eba47258">10.70.47.76:/bricks/brick0/testvol_brick0<name>10.70.47.76:/bricks/brick0/testvol_brick0</name><hostUuid>261b213b-a9f6-4fb6-8313-11e7eba47258</hostUuid></brick>
        </bricks>
        <optCount>1</optCount>
        <options>
          <option>
            <name>performance.readdir-ahead</name>
            <value>on</value>
          </option>
        </options>
      </volume>
      <count>1</count>
    </volumes>
  </volInfo>
</cliOutput>
[root@node31 ~]#