Update git submodules

Update git submodules

* Update docs/submodules/clamp.git from branch 'master'
  to 286492027e88f2463d6b91e670e6f5f3712888ab
  - Merge "Payload is expected as string in operational policy"
  - Payload is expected as string in operational policy

    1. converted json to string for legacy operational policy
    2. added payload data as default string value for generic operational policy

    Change-Id: If63423c24d736623b227537f0f83edeaac819215
    Issue-ID: CLAMP-831
    Signed-off-by: Vidyashree-Huawei <vidyashree.rama@huawei.com>