Send VM notification to VM call log tab.

We used to send them straight into call details to play the
voicemail. But, now we're removing that playback widget into
the call log, so that doesn't work anymore. Instead, drop them
into the call log.

- Remove superfluous interface.

Bug: 20433758
Change-Id: Icac220c65bb8ccf5589b4ae38db7b8c3fbf384f4