Revert "[2/2] Allow hiding frequently contacted lists"

This reverts commit 77ae8358d4a098c0d8695be77d2c52b1a56a0c36.

It hides the 'frequently contacted' list in the dialer unconditionally,
shouldn't be enabled by default anyway and is a questionable feature in
itself.

Change-Id: I39f8ac681f870ca8fd85ceb19073f54f766b2e1e