monitoring: Persist osd utilization
monitoring: Persist osd utilization

The patch persists osd utilization as part of
osd entity.

Change-Id: I54d7a6d66df3735e15707e101c4647cefe5641ca
Signed-off-by: anmolbabu <3d38fb1e9c5ff2662fc415254efcdfedb95b84d5@gmail.com>

skyrings/bigfin,skyrings/bigfin,skyrings/bigfin