Suggest "apc.slam_defense" off and "apc.write_lock" on

Summary: Ref T5501. These settings reduce error log noise.

Test Plan: Faked into this branch and hit the warning.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T5501

Differential Revision: https://secure.phabricator.com/D12319