Add CCR index privileges to Kibana Roles UI

[lcawl]

Kibana version:

6.5.0

Elasticsearch version:

6.5.0

Describe the bug:

Related to #25603 and elastic/stack-docs#149
There is a new manage_follow_index index-level privilege for cross-cluster replication in 6.5. It doesn't appear in the Kibana role management UI yet.

Steps to reproduce:

1. install Elasticsearch 6.5.
   2.install Kibana 6.5
2. Start trial license
3. Enable the security feature in Elasticsearch.
4. Create an index in Elasticsearch
5. Try to create a new role that has manage_follow_index index-level privileges for that index.

Expected behavior:

I expect that privilege to appear in the drop-down list.

[elasticmachine]

Pinging @elastic/kibana-security