Update git submodules

* Update docs/submodules/policy/engine.git from branch 'master'
  to b559c050557e757325743bd37b41fd49b01ba19a
  - Step snapshot version of policy engine
    
    Issue-ID: POLICY-1630
    Change-Id: Iefcaaf1811535e22904367b8d11346a02f5851c1
    Signed-off-by: liamfallon <liam.fallon@est.tech>
    
1 file changed