panko: Do db_sync in api manifest

panko: Do db_sync in api manifest

The db_sync from panko comes from the panko-api package; So we move the
db_sync to be done in the api manifest as it's done for other services
such as barbican.

This is necessary since in cases where the overcloud deploy requires
puppet to do the installations, with the previous setup it failed since
the command wasn't available in the step it was being done.

Change-Id: I20a549cbaa2ee4b2c762dbae97f5cbf4d0b517c8
Closes-Bug: #1671716
(cherry picked from commit d73c2630b534b277122db68620be8923c4d3a6b4)