Add instance_flavor_id to the notification message

Through Ceilometer,We can see the notification message just has
instance_type_id, for example,
    "instance_type" :"m1.nano"
    "instance_type_id": "6",
There is some confusion ,flavorid "42" should be added to the message.

bug 1217429

Change-Id: Id71e9480d243e7fc343bf9f7ea1faf2d87f01541
Merge "Add instance_flavor_id to the notification message"