Dialer: Handle "Unknown" and null numbers when adding to blacklist.

JIRA: BACON-278
Change-Id: I819968e06387b2cf4ddd9e9d47fdf87b6099a98b
Automatic translation import

Change-Id: Ie9fac7e47b7eb94cf7cd04a60ea897788ff781e3
[2/2] Dialer: Add a non-intrusive dialoger for incoming calls

Change-Id: Ibbb9653b4a1da12fe3a7ad8f98ecbb8bffb13311
Dialer: add Incoming Call Background (2/2)

Change-Id: I9f494385b53918c755cd9b12a0ecba989e153ad8