Update git submodules

* Update docs/submodules/bottlenecks from branch 'stable/fraser'
  - Change OS exporter

    1. The name of prometheus OS exporter is too long messing up
    the display of docker ps.
    2. Add version management of the exporter

    Change-Id: I3b634f2b3a274935ef27c0bcddeae3900170aebe
    Signed-off-by: Yang (Gabriel) Yu <Gabriel.yuyang@huawei.com>
    (cherry picked from commit 42a6613ff51c20c90f5c81348943f3de50f4b21c)

diff --git a/docs/submodules/bottlenecks b/docs/submodules/bottlenecks
index 3bf1544..8b8a2ca 160000 (submodule)
--- a/docs/submodules/bottlenecks
+++ b/docs/submodules/bottlenecks
@@ -1 +1 @@
-Subproject commit 3bf15446777a60510824e4b73da358934df03b98
+Subproject commit 8b8a2ca5a993b10f9c5cf3955b705fa2da024fe2