Different RBAC behavior between FTS backup/restore endpoints between 6.x.x and 7.0.0

What's the issue?
The available FTS endpoints which are used by 'cbbackupmgr' (depending on the cluster version) currently behave differently when using the 'Data Backup & Restore [*]' RBAC role.

A user with the 'Data Backup & Restore [*]' role is able to backup FTS aliases on a 6.x.x cluster whereas they are not on 7.0.0. Ideally these endpoints should exhibit the same behavior in this regard.

I've attached logs for 6.6.1 and 7.0.0 which displays this difference in behavior; both are using the same version of 'cbbackupmgr'. We see that the backup against 6.6.1 completes successfully, however, 7.0.0 fails with the following message:

Error backing up cluster: {"message":"Forbidden. User needs one of the following permissions","permissions":["cluster.fts!read"]}

Note that against the 6.6.1 cluster 'cbbackupmgr' is hitting the endpoint '/api/index' and against a 7.0.0 cluster 'cbbackpumgr' it's hitting the '/api/v1/backup' endpoint.

Please see MB-44965 for more information.