Update git submodules

* Update docs/submodules/portal.git from branch 'master'
  to dcd597990ae65dbe0c2ad73b401847a460f84422
  - Merge "Fix NPE & other sonar issues"
  - Fix NPE & other sonar issues

    A "NullPointerException" could be thrown
    Either log or rethrow this exception
    Use isEmpty() to check whether the collection is empty or not
    Replace the type specification in this constructor call with the diamond operator ("<>")

    Issue-ID: PORTAL-562
    Change-Id: I7a0317b66a66e2302c77d8244f4a01c93846c466
    Signed-off-by: Parshad Patel <pars.patel@samsung.com>