Create down-scaled bitmap for notification icon

Requires I0892357498db0ee89b8f4f9630dd980aa0f744ba

Phone app may have high resolution photo for contact picture, which
is not suitable for notification's large icon because it is too big.
This change lets the phone down-scale the picture and use it when
appropriate.

TESTED:
- make a phone call to the person whose contact picture is with higher
  resolution. Bail out of the in-call screen and see notification.
- miss a phone call from someone with higher resolution photo
- reboot the device before seeing missed-call notification. And check
  the notification after the reboot.

Bug: 6336293
Change-Id: I0892357498db0ee89b8f4f9630dd980aa0f744ba
5 files changed