During major upgrade of non-HA overcloud, paunch stops the
containerized mysql service, update container image and restart
the containerized mysql.
After a major update of mysql (e.g. 5.5 to 10.0), run mysql_upgrade
to ensure that database on-disk is upgraded to match the mysql
server version (e.g. update all MyISAM tables)
The mysql_upgrade cannot be performed during upgrade_steps because
paunch only runs during the deploy_steps. So run it in the
post_upgrade_steps, once we know paunch has updated mysql.
Change-Id: I6b6a531fd716ad9abcbf29886c0b1f2c64f04c9d
02f8609168