Cleanup dependencies for cinder-base

The python-cinder package now pulls the required dependency on
python-oslo-policy:

https://github.com/openstack-packages/cinder/blob/a22f32c619c94bf0ac188d4cdcf728c0e71152ea/openstack-cinder.spec#L143

TrivialFix

Change-Id: I504546e75b5a237fc4aac89bd9a5c34f09570817

docker/cinder/cinder-base/Dockerfile.j2

@@ -4,12 +4,10 @@ MAINTAINER {{ maintainer }}
 {% if install_type == 'binary' %}
     {% if base_distro in ['centos', 'fedora', 'oraclelinux', 'rhel'] %}
 
-# TODO(Martin) remove python-oslo-policy once RDO package is fixed
 RUN yum -y install openstack-cinder \
     python-automaton \
     lvm2 \
     ceph-common \
-    python-oslo-policy \
   && yum clean all \
   && mkdir -p /etc/ceph