This patch rename the v2.1 api policy with 'os_compute_api' prefix,
that used to distinguish with v2 and ec2 API. And also move all
v2.1 api policy rule out of policy.conf.
Partially implements bp v3-api-policy
Depends-On: Iec23b095176332414faf76a9c329f8bb5f3aa6c3
Change-Id: Id8e1e84cd3717dfd0a3b3f80acec50f96c205251