Add OSSN-0010 - Sample Keystone v3 policy exposes privilege escalation
vulnerability

This adds OSSN-0010, which covers a privilege escalation issue
associated with a sample Keystone v3 policy file.

Change-Id: I3213bbf4b9956b75d733f219660fcefe6a51848d
Related-Bug: #1287219
Merge "Add OSSN-0010 - Sample Keystone v3 policy exposes privilege escalation vulnerability"