ceph-osd: Add ulimit nofile on container start

ceph-osd: Add ulimit nofile on container start

On containerized deployment, the OSD entrypoint runs some ceph-volume
commands (lvm/simple scan and/or activate) which perform badly without
the ulimit option.
This option was added for all previous ceph-volume commands but not on
the ceph-osd container startup.
Also updating hard limit value to 4096 to reflect default baremetal
value.

Signed-off-by: Dimitri Savineau <dsavinea@redhat.com>
(cherry picked from commit 9a4ac46d1977726c6e9b0ce8e4f051f15ce2ca12)