While triaging bug 1768876 there was some concern
that change I8d426f2635232ffc4b510548a905794ca88d7f99
in Pike had regressed some behavior where a user that
does not explicitly request a specific AZ during server
create is then later restricted to only move operations
within that same AZ.
This test shows that is not a regression because the
AvailabilityZoneFilter looks at RequestSpec.availability_zone
rather than instance.availabililty_zone, so the instance
is free to be moved across zones.
As a result of the test, however, it was noticed that
the instance.availability_zone isn't updated during live
migration once the destination host is selected. The other
move operations like unshelve, evacuate and cold migrate
all update the instance.availabiltiy_zone, so this copies
the same logic.
Change-Id: I9f73c237923fdcbf4096edc5aedd2c968d4b893e
Closes-Bug: #1771860
Related-Bug: #1768876
(cherry picked from commit 0ed68c76fa)
(cherry picked from commit 133763d358)
ee07c1c67d