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

manifests/db/sync.pp

@@ -7,10 +7,10 @@
 # [*extra_params*]
 #   (Optional) String of extra command line parameters
 #   to append to the ceilometer-upgrade command.
-#   Defaults to '--skip-gnocchi-resource-types'.
+#   Defaults to undef.
 #
 class ceilometer::db::sync(
-  $extra_params = '--skip-gnocchi-resource-types',
+  $extra_params = undef,
 ) {
 
   include ::ceilometer::deps

spec/acceptance/ceilometer_wsgi_apache_spec.rb

@@ -47,6 +47,8 @@ describe 'ceilometer with mysql' do
         database_connection => 'mysql+pymysql://ceilometer:a_big_secret@127.0.0.1/ceilometer?charset=utf8',
 	sync_db             => false,
       }
+      # NOTE(tobasco): When running the beaker tests we need to exclude the
+      # gnocchi resource types since the acceptance test does not setup gnocchi itself.
       class { '::ceilometer::db::sync':
         extra_params => '--skip-gnocchi-resource-types',
       }

spec/classes/ceilometer_db_sync_spec.rb

@@ -6,7 +6,7 @@ describe 'ceilometer::db::sync' do
 
     it 'runs ceilometer-upgrade' do
       is_expected.to contain_exec('ceilometer-upgrade').with(
-        :command     => 'ceilometer-upgrade --skip-gnocchi-resource-types',
+        :command     => 'ceilometer-upgrade ',
         :path        => '/usr/bin',
         :refreshonly => 'true',
         :user        => 'ceilometer',