FROMGIT: fuse: Add initial support for fs-verity

This adds support for the FS_IOC_ENABLE_VERITY and FS_IOC_MEASURE_VERITY
ioctls. The FS_IOC_READ_VERITY_METADATA is missing but from the
documentation, "This is a fairly specialized use case, and most fs-verity
users won’t need this ioctl."

Cherry picked from 9fe2a036
https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git/log/?h=for-next



Bug: b/322046441
Test: ./cts-tradefed run commandAndExit cts -m CtsDexMetadataHostTestCases -t com.android.cts.dexmetadata.InstallDexMetadataHostTest

Change-Id: Ic4e0b52f57b2b0a5d16576f6551edd9dd9ff8dea
Signed-off-by: Richard Fung <richardfung@google.com>
Acked-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>