Add dialogs for spam report and block.

Screenshots:
1. block/report spam
https://screenshot.googleplex.com/5e772Kikikw
2. block
https://screenshot.googleplex.com/AEpYSYoL2E8
3. unblock(is spam and report not a spam)
https://screenshot.googleplex.com/AEZfhCXj4h8
4. unblock(not spam)
https://screenshot.googleplex.com/r7YkHuCMT1p
5. report not spam
https://screenshot.googleplex.com/jkcpm0pdKoj

Change-Id: I78fbbacece44632614026c03909289995bef5b14
Fix: 27295785