FsCrypt update: support fscrypt policies v1 and v2

This patchset introduces support decryption for Android 11.

In this update we deprecate ext4crypt. To specify the
policy version to use, use TW_USE_FSCRYPT_POLICY := 1 or
TW_USE_FSCRYPT_POLICY := 2. By default policy version will
be set to 2 if this variable is omitted.

Change-Id: I62a29c1bef36c259ec4b11259f71be613d20a112
diff --git a/crypto/fscrypt/MetadataCrypt.h b/crypto/fscrypt/MetadataCrypt.h
index cd0f5e5..0370664 100644
--- a/crypto/fscrypt/MetadataCrypt.h
+++ b/crypto/fscrypt/MetadataCrypt.h
@@ -19,7 +19,17 @@
 
 #include <string>
 
+#include "KeyBuffer.h"
+#include "KeyUtil.h"
+
+
 bool fscrypt_mount_metadata_encrypted(const std::string& block_device,
                                       const std::string& mount_point, bool needs_encrypt);
 
+bool defaultkey_volume_keygen(KeyGeneration* gen);
+
+bool defaultkey_setup_ext_volume(const std::string& label, const std::string& blk_device,
+                                 const KeyBuffer& key,
+                                 std::string* out_crypto_blkdev);
+
 #endif