overlay: Remove voicemail number configs

 * This is not a thing since 2016.

This reverts commit 8d446d533d48776a55121499bb557f8d5517f8e1 and f61c4532dca095c32a78b7ea3385a295073ea807.

Change-Id: Ie870f0c486043b57e4b8b10693830331540ae013
4 files changed