Update git submodules

* Update docs/submodules/bottlenecks from branch 'stable/fraser'
  - add openstack-export support

    add openstack-exporter and enable ovs plugin in Barometer

    Changes:
    1. Add openstack-exporter docker
    2. Add opnestack grafana dashboard

    Change-Id: Ifd3416ad1dc48075e98c190b2048c7760f686bcb
    Signed-off-by: Yang (Gabriel) Yu <Gabriel.yuyang@huawei.com>
    (cherry picked from commit b1b458428b644e0df7957e3137bc75d658d68ab1)

diff --git a/docs/submodules/bottlenecks b/docs/submodules/bottlenecks
index 316f537..dba21d5 160000 (submodule)
--- a/docs/submodules/bottlenecks
+++ b/docs/submodules/bottlenecks
@@ -1 +1 @@
-Subproject commit 316f53716106bbcff780761ee1d24a610cc0e925
+Subproject commit dba21d5d8e56ee647de0e167bd106426be734c2f