auto_disk_config image property incorrectly treated as boolean during rescue mode boot

[Brian Rosmaita]

Introduced in Kilo release here:
https://github.com/openstack/nova/blame/90e1eacee8da05bed2b061b8df5fc4fbf5057bb2/nova/virt/xenapi/vmops.py#L707

The auto_disk_config value is a string on the image, but is being used as if it were a boolean value. As a result, even an auto_disk_config value of "False" on the image will result in nova attempting to resize the root disk.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/208642

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/208642
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=20847c25a8157a10b765387ff8dbda31f8f4e91a
Submitter: Jenkins
Branch: master

commit 20847c25a8157a10b765387ff8dbda31f8f4e91a
Author: Andrew Laski <email address hidden>
Date: Mon Aug 3 16:29:39 2015 -0400

    Xen: convert image auto_disk_config value to bool before compare

    During rescue mode the auto_disk_config value is pulled from the rescue
    image if provided. The value is a string but it was being used as a
    boolean in an 'if' statement, leading it to be True when it shouldn't
    be. This converts it to a boolean value before comparison.

    Change-Id: Ib7ffcab235ead0e770800d33c4c7cff131ca99f5
    Closes-bug: 1481078