cryptfs: Require ext disk crypt to match code

Our external partitions have no crypto header/footer, so we
only get the keysize and key.  Our code has been implicitly
assuming that this keysize off of disk matches the crypto
type we have in our code (and thus matches the keysize our
code is using as well).  We now make this assumption
explicit, and check for this and no longer allow external
code to pass a keysize in to cryptfs.

Bug: 73079191
Test: Compiled and tested in combination with other CLs.
Change-Id: I1a1996187e1aaad6f103982652b1bcdfd5be33ce
4 files changed