Add notify to mariadb_galera_configuration

Need to trigger a restart after changing the galera configuration.

Change-Id: Ie148e8dce2e945ea956f6521c04bfc031f9da3f2

recipes/mariadb-cluster-server.rb

@@ -60,6 +60,7 @@ mariadb_galera_configuration 'MariaDB Galera Configuration' do
   gcomm_address gcomm_address
   wsrep_provider_options provider_options
   wsrep_sst_method 'rsync'
+  notifies :restart, 'service[mysql]', :immediately
 end
 
 # Install clustercheck tool

spec/mariadb-cluster-server_spec.rb

@@ -26,6 +26,10 @@ describe 'openstack-ops-database::mariadb-cluster-server' do
       )
     end
 
+    it do
+      expect(chef_run.mariadb_galera_configuration('MariaDB Galera Configuration')).to notify('service[mysql]').to(:restart).immediately
+    end
+
     it do
       expect(chef_run).to create_if_missing_cookbook_file('/usr/bin/clustercheck').with(
         source: 'clustercheck',