containers: bump memory limit
containers: bump memory limit

A default value of 4GB for MDS is more appropriate and 3GB for OSD also.

Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1531607
Signed-off-by: Sébastien Han <62d754cc350e84d3b1c32ae79f976f5348e74a40@redhat.com>

ceph/ansible-ceph-osd