Eleven: AlbumScrimImage: generate drawable for default artwork

Instead of using a huge PNG for the default artwork, generate
a simple color drawable (rgb(50,60,70) / #323c46).

This change also renames all "blur" references because they are not
valid as the AlbumScrimImage has only optional blur these days.

Change-Id: I9cedcbca0621b06ad0a505a3edee9cbf7cc298d2
Signed-off-by: Alexander Martinz <amartinz@shiftphones.com>