Make DrydockLog policy-aware
Summary: Ref T2015. Update DrydockLog for policy awareness and give it a policy query.
Test Plan: Browsed all the log interfaces.
Reviewers: btrahan
Reviewed By: btrahan
CC: hach-que, aran
Maniphest Tasks: T2015
Differential Revision: https://secure.phabricator.com/D7831