Currently, "Resize instance" widget is not working because it relies on
legacy Nova API v2.46, obsoleted in Pike release. Proposed patch make
Horizon use current Nova API (>=2.47).
Note: It also cherry-picks a7956cd004 from the master branch
which avoids the extra call of flavor_get in resize server form.
Closes-Bug: #1940834
Co-Authored-By: Akihiro Motoki <amotoki@gmail.com>
Change-Id: Id2f38acfc27cdf93cc4341422873e512aaff716a
(cherry picked from commit d269b1640f)
(cherry picked from commit 920cbb82d2)