AnkiDroid does not support .anki Tried to import .anki files  didn't work  kind of dumb when your apps name is AnkiDroid  no? Only .akpg is allowed. The developer's comments made clear why it did not work  however backwards compatibility might be more helpful than a guide on how to convert the old format to the new one. This particular deck I could not find in any other format  and converting was honestly not something I had thought of.
April 12 2016