Adapt to underlying changes in the PBKDF2 implementation

We need to specify "PBKDF2WithHmacSHA1And8bit" now in order to get precisely
the same output as was previously generated with "PBKDF2WithHmacSHA1".  We
also now try both when it's ambiguous which was used to generate the archive
checksums.

Bug 12494407

Change-Id: I5443f31a5e13c24f44445768b6e9a6eea221ede6