Update git submodules

Update git submodules

* Update docs/submodules/policy/engine.git from branch 'master'
  to 0c20d1c294fe146e1018f14b07a8d861c29fe527
  - JUnit/SONAR/Checkstyle in ONAP-REST

    Third batch of JPA pojos (E-M), with JUnit added and SONAR/Checkstyle
    issues addressed. In cases where a class name change caused an update in
    another package, the license header on files for those knock on changes
    are not updated.

    Issue-ID: POLICY-2131
    Change-Id: I4fee1e9fb9c8a69dd6f2f15d3e3a8844473b857b
    Signed-off-by: liamfallon <liam.fallon@est.tech>