Fix typo in Android Keystore KeyFactory exception message.

The typo was pointed out by kroot@ in code review of
4ecd092226fbd748b4a26f3bbb5c4d25a3488fff after it was submitted.

Bug: 18088752
Change-Id: I50d2fa93e1a2d352fe432e34ce98add82a71c483
1 file changed