EDIT: Definitely was Bitcoin Mobile Wallet, along with the others, which was base64 aes-256 encrypted. I found out using openssl, but the passwords I remember were incorrect, so they're lost unless I can remember them.
If you mean you were using Bitcoin Wallet for Android by Andreas Schildbach then did openssl display a "bad decrypt" error when you tried derypting a file?
enter aes-256-cbc decryption password:
bad decrypt
If it didn't show the quoted error maybe there's still hope. When I tested decrypting some wallet files I found you had to open the decrypted file in an editor like notepad++ to see the 12 wallet words that you can use to recover your coins with. If you open it in the ordinary notepad editor that comes pre-installed on windows it doesn't show the 12 words.
These are my instructions.
https://bitcointalk.org/index.php?topic=1822148.msg18191881#msg18191881