[TrivialFix] Move security group tests into correct test file

This commit moves security group tests currently in test_server_rbac
into test_security_groups_rbac as that is the logical place
for the tests. And this commit renames the deprecated security
groups test class to avoid a name conflict with the non-deprecated
test class.

Change-Id: Iae32d9bc7e22e39415e498e44f0da4f2711dc550
2 files changed