Update git submodules

Update git submodules

* Update docs/submodules/clover from branch 'stable/fraser'
  - Merge "Add index and cleanup design docs on stable/fraser" into stable/fraser
  - Add index and cleanup design docs on stable/fraser

    - Add toplevel index to design docs on stable/fraser
    - Add headers to each of the design docs
    - Added usage of Clover container to install Jaeger/Prometheus
    in combination in tracing and monitoring docs
    - Minor edits including removing TODO/TBD

    Change-Id: I1a33544a5b3d6be4147810ef9472b8d72cdec28c
    Signed-off-by: Eddie Arrage <eddie.arrage@huawei.com>