When voicemail number is unknown, show voicemail setup on notification click.

1. In NotificationMgr changed intent when no voicemail number is found so
that it will trigger opening of the voicemail screen.
2. In CallFeaturesSetting added new intent extra to indicate we just want
to open the voicemail settings.  This intent is used by Google Voice, and
I wanted to ensure that the code path for that case is not changed, hence
the new extra.

Bug: 17795834
Change-Id: I62b3d6c99558dc698565459aa0d43cd4efdd6fdd
4 files changed