Log starting tab.

Log which tab is presented when app first launched, including:
- speed dial
- call log
- contacts
- voicemail (if not available, we move to contacts tab immediately and log the
move)

Test: manual

PiperOrigin-RevId: 159754375
Change-Id: Ice5be6c0f2c0463204fe3c1c7cf83c4dfc7df5d1