Update git submodules

* Update docs/submodules/policy/parent.git from branch 'master'
  to ed57ed2df0db5dc0bbf339b6ff51c4279396cba1
  - Add report-aggregate sonar execution

    This seems to bump the xacml-pdp coverage back to where
    it was previously. No effect on common, models, api, pap
    or drools. Potentially this could help engine.

    Not sure exactly how Jacoco now seems to find the coverage.

    Does not solve cross sub-module lack of coverage. Will
    continue investigating.

    Issue-ID: POLICY-2321
    Change-Id: Id71a2f06f30491246504cb2881b94fe11ad5f501
    Signed-off-by: Pamela Dragosh <pdragosh@research.att.com>