Update git submodules

* Update docs/submodules/bottlenecks from branch 'master'
  - 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>

diff --git a/docs/submodules/bottlenecks b/docs/submodules/bottlenecks
index 265d35d..b1b4584 160000 (submodule)
--- a/docs/submodules/bottlenecks
+++ b/docs/submodules/bottlenecks
@@ -1 +1 @@
-Subproject commit 265d35dd56247e855002c05cc4f11b39514700c5
+Subproject commit b1b458428b644e0df7957e3137bc75d658d68ab1