Update character set and coallaction for mysql5.7
Update character set and coallaction for mysql5.7

Our character set and collaction are also kept in the older version
(possibly mysql5.5), which makes it impossible for us to create new
character set and collaction through database-create. At the same
time, we can't display these manually created database.

Update here. More information comes from:
https://dev.mysql.com/doc/refman/5.7/en/charset-charsets.html

Change-Id: I14c0392e19c7846c7aed1e60fe5b5ca01f22a2f4

openstack/trove,openstack/trove