FastBitmapDrawable can draw an icon badge (notification count)

- Added BadgeInfo to contain data to be shown in a badge
  (currently just notification count).
- Added BadgeRenderer in DeviceProfile to contain things
  relevant to drawing the badge, such as size and Paint's.
- Added IconPalette to compute colors for the badge based
  on a dominant color (will also be used for notifications)
- FastBitmapDrawable uses these classes to draw the badge.

Bug: 32410600
Change-Id: I6595a4879943357590f7d20c22594691a573ecaf