use pool_names.yml to populate vars in upgrade.yml

[chengtcli]

pool_names.yml has all tasks those populate vars, so we use pool_names.yml to populate vars instead of using ceph-osd role.

Also prevent running pool_names.yml more than one time.

[bbc-jenkins]

Can one of the admins verify this patch?

• \"ok to test\" to accept this pull request for testing
• \"test this please\" for a one time test run
• \"add to whitelist\" to add the author to the whitelist

[bbc-jenkins]

Can one of the admins verify this patch?

• \"ok to test\" to accept this pull request for testing
• \"test this please\" for a one time test run
• \"add to whitelist\" to add the author to the whitelist

[bbc-jenkins]

Can one of the admins verify this patch?

• \"ok to test\" to accept this pull request for testing
• \"test this please\" for a one time test run
• \"add to whitelist\" to add the author to the whitelist

[chengtcli]

upgrade passed on cisdev with this fix

[nirajdp76]

ok to test