Handles onFailure case of getting wallpaper color

- Use a fixed bitmap size to be stored, so that the full preview won't decode the asset, uses tha catched result.
- If returns null wallpaper color, uses light color as default.

Test: Manually
Fixes: 157889638
Change-Id: I7c9496949d35061049e380f4d21621610590e6b7
4 files changed