Fix etcd_init_task volume
Fix etcd_init_task volume

Docker puppet hook writes to /etc of
containers. Mount /etc as rw for etcd container.

Change-Id: I8e45de18a91022690c19888cbfaa68d2fdfe46ce
Signed-off-by: Bogdan Dobrelya <a2228ae37d00d1cbd5a93e53f3e1e5aef21d5900@redhat.com>

dprince/tripleo-heat-templates,openstack/tripleo-heat-templates,dprince/tripleo-heat-templates,openstack/tripleo-heat-templates