Add specific exception for wrong final block length

EVP_DecryptFinal_ex can have an error on the wrong block length at the
end of a decrypted block, so throw IllegalBlockSizeException when that
happens instead of a RuntimeException.

Bug: 10610957
Bug: https://code.google.com/p/android/issues/detail?id=58396
Change-Id: I70ea040c3b52fc30591963270850871a8cc581d3
Add expectations for three known CharsetDecoder-/CharsetEncoder-related failures.

Bug: 10666742
Change-Id: I3f93546f814c5b493ad3738eebf8e792f661970c

Conflicts:
	expectations/knownfailures.txt
Make documentation on InputStream#skip more clear

On first reading the documentation for InputStream#skip seemed to imply
that 0 was only returned when n was 0. Reworded this to make it clearer
to the reader that sentence only applies when n is less than 0.

Change-Id: I5b3d70f87551cc54d80da7d978c2187a78bc39c1
Update CipherInputStream to use AES instead

The RI won't use DES cipher anymore, so update to use AES so we can
continue to test.

Change-Id: Ib39b0c0653911ed675dc8b5b0120c66714d0f1fa