Remove unused medialog service

This service is not actually started/used, so removing it from source,
as it is a maintenance burden/ownerless. Out of process logging has been
superseded by mediametrics.

Bug: 284657986
Bug: 285414783
Flag: EXEMPT cleanup
Test: Compiles
Change-Id: I24dd3ee3e4561c0288250624d8ce90c1f1eeabb2