RPC Registration changes for clustering
1. Unregisters rpcs for master/equal to slave scenario as well.
2. Made RpcManager as the device-context-closed-handler , instead of the RpcContext
3. If Role Change fails after several attempts on a switch, the device context is closed. This is to avoid rpcs getting registered in wrong nodes.
4. Removed debug exception for device close in RoleManagerImpl
5. Addition of Logs
Change-Id: Ie5af7466b1422698d3c3287195d237fe1407b023
Signed-off-by: Kamal Rameshan <kramesha@cisco.com>