Fix /servers/<instance-id>os-security-groups using quantum

When using quantum security groups:
	GET /servers/<instance-id>/os-security-groups
aways returns an empty list. This patch adds a call to
get_instance_security_groups in the api implemenation of security groups.
This method passes both the instance_id and instance_uuid so the api layer
does not need to be aware of which underlying implementation is being used.
The instance_id is needed when using nova and when using quantum the
instance_uuid is needed so both need to be passed.

Fixes bug 1159793

Change-Id: I372adcf93c55d4e6469ef08429ec260d3387f9fe
Merge "Fix /servers/<instance-id>os-security-groups using quantum" into milestone-proposed