ANDROID: block: provide key size as input to inline crypto APIs

Currently, blk-crypto uses the algorithm to determine the size of keys.
However, some inline encryption hardware supports protecting keys from
software by wrapping the storage keys with an ephemeral key.  Since
these wrapped keys are not of a fixed size, add the capability to
provide the key size when initializing a blk_crypto_key, and update the
keyslot manager to take size into account when comparing keys.

Bug: 147209885

Change-Id: I9bf26d06d18a2d671c51111b4896abe4df303988
Co-developed-by: Gaurav Kashyap <gaurkash@codeaurora.org>
Signed-off-by: Gaurav Kashyap <gaurkash@codeaurora.org>
Signed-off-by: Barani Muthukumaran <bmuthuku@codeaurora.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>