Update git submodules

Update git submodules

* Update docs/submodules/policy/parent.git from branch 'master'
  to 324700e31ee692899c1658bf647963ca04ffa425
  - Consolidate checkstyle plugin into policy parent

    At the moment, the checkstyle plugin definitions are repeated separately
    in all the policy components. This review adds the checkstyle plugin
    defintions into policy parent.

    Subsequent reviews will remove it from the individual component repos.

    Issue-ID: POLICY-2188
    Change-Id: I7e786e82086d31df8597c08382bfe839e60074e3
    Signed-off-by: liamfallon <liam.fallon@est.tech>