use service type constants from neutron_lib plugins

The well known service type constants are in
neutron_lib.plugins.constants, but for legacy reasons a few still exist
and are referenced from neutron_lib.constants [1] that we'd like to
remove.

This patch switches references over to neutron_lib's plugin constants.

[1] https://github.com/openstack/neutron-lib/blob/master/neutron_lib/constants.py#L353

Change-Id: Ib44f6fb67a1232eceb300e0c8c65b9beb0a899af

neutron_vpnaas/tests/unit/db/vpn/test_vpn_db.py

@@ -464,7 +464,7 @@ class VPNPluginDbTestCase(VPNTestMixin,
         self.plugin = vpn_plugin.VPNPlugin()
         ext_mgr = api_extensions.PluginAwareExtensionManager(
             extensions_path,
-            {lib_constants.CORE: self.core_plugin,
+            {nconstants.CORE: self.core_plugin,
              nconstants.VPN: self.plugin}
         )
         app = config.load_paste_app('extensions_test_app')
@@ -1763,7 +1763,7 @@ class TestVpnDatabase(base.NeutronDbPluginV2TestCase, NeutronResourcesMixin):
         super(TestVpnDatabase, self).setUp(self.plugin_str)
         # Get the plugins
         self.core_plugin = directory.get_plugin()
-        self.l3_plugin = directory.get_plugin(lib_constants.L3)
+        self.l3_plugin = directory.get_plugin(nconstants.L3)
 
         # Create VPN database instance
         self.plugin = vpn_db.VPNPluginDb()

neutron_vpnaas/tests/unit/db/vpn/test_vpn_validator.py

@@ -18,7 +18,6 @@ import socket
 
 from neutron.db import l3_db
 from neutron.db import servicetype_db as st_db
-from neutron_lib import constants as lconstants
 from neutron_lib import context as n_ctx
 from neutron_lib import exceptions as nexception
 from neutron_lib.plugins import constants as nconstants
@@ -77,8 +76,8 @@ class TestIPsecDriverValidation(base.BaseTestCase):
         super(TestIPsecDriverValidation, self).setUp()
         self.l3_plugin = mock.Mock()
         self.core_plugin = mock.Mock()
-        directory.add_plugin(lconstants.CORE, self.core_plugin)
-        directory.add_plugin(lconstants.L3, self.l3_plugin)
+        directory.add_plugin(nconstants.CORE, self.core_plugin)
+        directory.add_plugin(nconstants.L3, self.l3_plugin)
         self.context = n_ctx.Context('some_user', 'some_tenant')
         self.service_plugin = mock.Mock()
         self.validator = vpn_validator.IpsecVpnValidator(self.service_plugin)

neutron_vpnaas/tests/unit/services/vpn/service_drivers/test_ipsec.py

@@ -15,8 +15,8 @@
 
 import mock
 
-from neutron_lib import constants
 from neutron_lib import context as n_ctx
+from neutron_lib.plugins import constants
 from neutron_lib.plugins import directory
 from oslo_utils import uuidutils
 

neutron_vpnaas/tests/unit/services/vpn/service_drivers/test_vyatta_ipsec.py

@@ -15,8 +15,8 @@
 #
 
 import mock
-from neutron_lib import constants
 from neutron_lib import context as n_ctx
+from neutron_lib.plugins import constants
 from neutron_lib.plugins import directory
 from oslo_utils import uuidutils