VMware: Update flavor-related metadata upon instance resize

[Ivaylo Mitev]

Steps to reproduce
==================
* Create an instance using a certain flavor
* Resize the instance using a different flavor

Expected result
===============
The flavor-related metadata must be updated to represent the newly selected flavor upon resize.

Actual result
=============
The metadata of the corresponding vSphere VM (kept in the notes of the VM) keeps holding the values for the initial flavor.

Environment
===========
1. Exact version of OpenStack you are running.
Queens

2. Which hypervisor did you use?
vSphere 6.5

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/681004

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/681004
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=4141bf63af1ea6664db756be859d0bb845a692b9
Submitter: Zuul
Branch: master

commit 4141bf63af1ea6664db756be859d0bb845a692b9
Author: Ivaylo Mitev <email address hidden>
Date: Thu Aug 29 04:30:48 2019 -0700

    VMware: Update flavor-related metadata on resize

    Update the flavor-related metadata in the VM Notes in vSphere upon
    instance resize. Otherwise, notes keep holding the previous flavor's
    name and size.

    Change-Id: Ib3c8d15f8073928a47ee860409a999a06acfc1a1
    Closes-Bug: #1843265