Change cryptfs changepw to only require a new password.

The master key is now stored unhashed in memory. This
is needed because certain operation like remote reseting
of passwords the old password is not avaliable.
The changepw interface has been changed to only take
the new password as the only argument. When this is
called we reencrypt the master key with the new password
and old salt.

Bug: 3382129
Change-Id: I9a596b89013194605d6d7790067691aa0dc75e72
3 files changed