FBE for Pixel 2

Includes various minor fixes for building in Android 8 trees with r23+ tag

Update FBE extended header in libtar to version 2 and include the entire
ext4_encryption_policy structure now after translating the policy.

See this post for more details:
https://plus.google.com/u/1/+DeesTroy/posts/i33ygUi7tiu

Change-Id: I2af981e51f459b17fcd895fb8c2d3f6c8200e24b
diff --git a/libtar/libtar.h b/libtar/libtar.h
index 2d0a3d3..aa637b1 100644
--- a/libtar/libtar.h
+++ b/libtar/libtar.h
@@ -21,8 +21,7 @@
 #include "libtar_listhash.h"
 
 #ifdef HAVE_EXT4_CRYPT
-#define EXT4_KEY_DESCRIPTOR_SIZE 8
-#define EXT4_KEY_DESCRIPTOR_HEX 17
+# include "ext4crypt_tar.h"
 #endif
 
 #ifdef __cplusplus
@@ -70,7 +69,7 @@
 	char *gnu_longlink;
 	char *selinux_context;
 #ifdef HAVE_EXT4_CRYPT
-	char *e4crypt_policy;
+	struct ext4_encryption_policy *eep;
 #endif
 	int has_cap_data;
 	struct vfs_cap_data cap_data;