chore(datastore): migrate region step 1 - add new region datastore_ndb_django_middleware (GoogleCloudPlatform#12802)

Author: eapl-gemugami

datastore/cloud-ndb/django_middleware.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+# [START datastore_ndb_django_middleware]
 # [START ndb_django_middleware]
 from google.cloud import ndb
 
@@ -29,3 +30,4 @@ def middleware(request):
 
 
 # [END ndb_django_middleware]
+# [END datastore_ndb_django_middleware]