Match fab configuration for SM installation

Issue: Certain tuning configuration for ceph is done via but not
    via SM installation.

Closes-Bug: #1384779

Fix: Added the new configuration to init.pp of ceph module.

Unit Testing: provisioned cluster via ceph and verified the
    configuration admin socket.

root@cmbu-cl73:~# ceph --admin-daemon /var/run/ceph/ceph-osd.6.asok
config show | grep threads
  "osd_op_threads": "4",
  "osd_disk_threads": "2",
root@cmbu-cl73:~# ceph --admin-daemon /var/run/ceph/ceph-osd.7.asok
config show | grep rbd
  "rbd_cache": "true",
  "rbd_cache_size": "536870912",

Change-Id: Icb7d248c1c14b25afb873337b3f8835f3770a2fb
Merge "Match fab configuration for SM installation"