hw_video:ram_max_mb is tracked for quota but not compute node resource provider allocations

Related fix proposed to branch: master
Review: https://review.openstack.org/483133

Reviewed: https://review.openstack.org/483133
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=f9eea8869eabf12d3e1a078bd48fa96f0badb1ed
Submitter: Jenkins
Branch: master

commit f9eea8869eabf12d3e1a078bd48fa96f0badb1ed
Author: Matt Riedemann <email address hidden>
Date: Wed Jul 12 19:44:34 2017 -0400

    Stop counting hw_video:ram_max_mb against quota

    The hw_video:ram_max_mb flavor extra spec is only used by the
    libvirt driver and was added back in Icehouse as part
    of blueprint libvirt-video-driver-selection.

    For whatever reason, it was used to count against a project's
    ram quota when an instance was created but failed to be
    accounted for during an instance delete, at least until that
    bug was fixed over 3 years later in Pike with commit f2d03bf92.

    This is the only flavor extra spec that is counted against
    quota in the API and is only used by a single virt driver.
    If something like this is going to actually be counted, it
    should probably be as part of the overhead calculation that
    happens in the compute service as part of the resource claim
    on the host.

    Also note that this is not counted as part of the MEMORY_MB
    allocation record for the instance with the Placement service,
    which means it's not accounted for when scheduling and selecting
    a destination host.

    With blueprint cells-count-resources-to-check-quota-in-api changing
    how we count quota usage from the API, this special snowflake will
    also cause problems as it's not tracked in the instances table
    record like vcpus and memory_mb are tracked, so we'd have to slow
    down the DB queries by doing extra joins for flavor extra specs
    to account for this extra overhead that is probably rarely used
    in most deployments, which is even more apparent given the
    usage decrement issue wasn't fixed until over 3 years after the
    feature was added.

    Therefore this change removes the counting of the hw_video:ram_max_mb
    flavor extra spec value against the project quota in the API.

    Related-Bug: #1681989
    Related-Bug: #1704012

    Related to blueprint cells-count-resources-to-check-quota-in-api

    Change-Id: Iad631f0f775df6263ea730cadca5b089ce859b9b