Update git submodules

Update git submodules

* Update docs/submodules/ccsdk/cds.git from branch 'master'
  to 88e3ef2d396bc91051b182d11a2d490bf37abf08
  - Merge "Rolling upgrade support for in-flight requests"
  - Rolling upgrade support for in-flight requests

    Three entry points are being handled :
     1 - REST endpoint
     2 - gRPC endpoint
     3 - Kafka consumer

    We make use of Phaser object to make sure the PreDestroy callback wait
    for all requests to be executed before stopping the process.

    The docker image was also modified to make sure the java process becomes
    PID 1 in the container in order to catch the SIGTERM signal which
    triggers the PreDestroy callback of Spring. This was done by using
    the "exec" command in bash.

    Issue-ID: CCSDK-1885
    Signed-off-by: Sebastien Premont-Tendland <sebastien.premont@bell.ca>
    Change-Id: I3e2a72e26a4c8b7768ebc374ea40aa8d55fb6761