Clarify some IpManager/ApfFilter debugging output.

Test: as follows
    - built
    - flashed
    - booted
    - "runtest frameworks-net" passes
    - "adb shell dumpsys wifi ipmanager" shows updated output
Bug: 34793131
Change-Id: I6dec135b97343943efb421ef7b2e84c4751dd5ea
(cherry picked from commit af579eb5)