Do not skip gnocchi resource type creation by default in db::sync

Do not skip gnocchi resource type creation by default in db::sync

The default command-line option for ceilometer-upgrade is to not
skip gnocchi resource type creation. If we do not pass any extra_params
to the ceilometer::db::sync class, we should keep defaults.

This has not failed before in CI because p-o-i was passing
'--skip-metering-database' as extra_params, but now we are removing
that deprecated option in [1].

[1] - https://review.openstack.org/548337

Change-Id: I33c1667e19326ec67c5cf953daa1237175895c4f