vold: Wrapped key support for metadata encryption

metadata_encryption fstab option provides details on the cipher
and flags used for metadata encryption. wrappedkey_v0 is provided
to dm-default-key dm device when a wrapped key is used. The
inline encryption hardware unwraps the key and derives the
encryption key used to encrypt metadata without returning the key
in the clear to software.

Bug: 147733587
Test: FBE with metadata encryption using wrapped keys.
Change-Id: Ibf69bdc12bb18d2f0aef8208e65f3a8dececfd2a