Change default policy to allow create_samples
Change default policy to allow create_samples

https://review.openstack.org/#/c/234823/ has broken heat
integration tests as the default policy no longer allows
to create_samples without admin privileges.

Change-Id: I28980ff4cd82950bc713da519e0e49b62fc77a22
Closes-Bug: #1551383
ityaptin/ceilometer,idegtiarov/ceilometer,ityaptin/ceilometer,openstack/ceilometer,openstack/ceilometer,idegtiarov/ceilometer