Health Warn mons x,x, are low on available space OCS 4.x (host mounted mons)

Issue

• In Openshift Container Storage (OCS) 4. MONs not using PV's but rather are host mounted, print the following warning:

# ceph status
    health: HEALTH_WARN
            mons x,x are low on available storage

# ceph health detail
HEALTH_WARN mons a,b,c are low on available space
MON_DISK_LOW mons a,b,c are low on available space
    mon.a has 30% avail
    mon.b has 29% avail
    mon.c has 23% avail