Ansible role ceph-mgr name is colliding with same name in ceph-ansible

The ceph-mgr role has a name colliding with the similarly named role brought by ceph-ansible, which makes it very difficult (aka next to impossible without dirty Ansible tricks, which doesn't foresee to have different roles having the same name) to have an integrated automation approach to Ceph deployment.

Start by locating the ceph-mgr Ansible role and all references to its name in this repository, then compare them with the similarly named role supplied by ceph-ansible. Confirm how the role is selected during an integrated Ceph deployment; done means both roles can coexist without name collisions and the repository's references remain consistent.

Written by the indexing model from the issue text.