Blocked Numbers A11Y fixes & polish.

- Increase touch target for x button.
- Make all phone numbers read as phone numbers.
- Format numbers as phone numbers as they are entered
  then strip formatting before writing to provider.
- Change padding of add blocked number dialog.

- Depend on provider api isntead of directly checking if isPrimaryUser

Yet to add snackbars.

Bug: 27709645
Bug: 27495710
Change-Id: I217a3c0332c97e515407f4b4c07b614c59c2d9cf