Deleting 'default' security group of a non-admin tenant by admin is not working

[Babu Shanmugam]

There are some contradictory behaviour of the 'default' security group created for each tenant when compared with OVS neutron plugin. With OVS plugin, the admin user can delete the 'default' SG of any tenant except its own. Where as, contrail does not allow for the admin user to delete the default SG of other tenants.
After deleting the 'default' SG by admin, following scenarios were observed.

1. Create a new SG with name 'default' - Denied with reason "Default security group already exists."
2. Show 'default' SG - Shows a newly created 'default' SG details
3. List SGs - List result includes newly created 'default' SG
4. Update 'default' SG - Updates a newly created SG
5. SG rule-list - Does not include the rules that belonged to 'default' group
6. SG rule-create - Creates a rule and adds to the newly created 'default' SG group's rules.

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/5189
Committed: http://github.org/Juniper/contrail-controller/commit/50e23cb8af5f0cccf50dfb82fbb936d732c1a78e
Submitter: Zuul
Branch: master

commit 50e23cb8af5f0cccf50dfb82fbb936d732c1a78e
Author: Babu Shanmugam <email address hidden>
Date: Wed Dec 3 08:31:43 2014 +0000

Fix contradictory behaviour of default security group

Closes-Bug: #1398732

Change-Id: I0f0fb12aa3e65fb38d0237ba349075f3e802ee6f