Bump neutron to 0.3.15

This sync asap2 patch to community work
diff --git a/charts/neutron/Chart.yaml b/charts/neutron/Chart.yaml
index f5f34be..a39d84f 100644
--- a/charts/neutron/Chart.yaml
+++ b/charts/neutron/Chart.yaml
@@ -9,4 +9,4 @@
 sources:
 - https://opendev.org/openstack/neutron
 - https://opendev.org/openstack/openstack-helm
-version: 0.3.13
+version: 0.3.15