Remove the 'os_compute_api:os-flavor-manage' policy.
The 'os_compute_api:os-flavor-manage' policy has been deprecated
since 16.0.0 Pike.
The policy has been replaced with the following policies.
- os_compute_api:os-flavor-manage:create
- os_compute_api:os-flavor-manage:delete
Change-Id: I856498dfcebfa330598a22dd7c660bd6f158351b