Fix glance configuration for ceilometer

Modify /etc/glance/glance-api.conf, not /etc/ceilometer/ceilometer.conf.

Change-Id: I3725a6578fcad6c49b2fc1cd9495d391157e714b
Closes-Bug: #1269657
backport: havana
Update the glance notifier option for icehouse

The notifier_strategy option is deprecated, replaced by the
notification_driver option.

Change-Id: I1bd2c777dc7e502fc9774a75230b9e516631207f
Merge "Fix glance configuration for ceilometer"
Merge "Update the glance notifier option for icehouse"