Set "glare" as valid choice for "--murano-packages-service" option
Set "glare" as valid choice for "--murano-packages-service" option

This commit adds "glare" to valid choices list for option
"--murano-packages-service". This value is already supported in
client's code but not allowed in CLI.

Change-Id: I4976711d3cec1f7799f34c60500193d4ecd2a6b2
Closes-bug: #1561072

openstack/python-muranoclient,openstack/python-muranoclient