Remove D-Bus policy configuration for org.genivi.persistence.admin

The policy file is never installed by Makefile and it is
persistence-common-object that takes the name so policy should probably be
in that repository. Remove from pcl for less confusion.

See GENIVI/persistence-common-object#8 for more details.

Signed-off-by: Martin Ejdestig <[email protected]>

Author: martin-ejdestig