Add support for metadata encryption

Support encrypting metadata in /userdata using the dm-default-key
driver with a key in the /metadata partition.

Bug: 29189559
Test: Angler & Marlin build and boot
Change-Id: I716b117508d4bb4f6a4039293acb848cbc60f67b
diff --git a/Android.mk b/Android.mk
index ca0a21b..69be87d 100644
--- a/Android.mk
+++ b/Android.mk
@@ -33,6 +33,7 @@
 	ScryptParameters.cpp \
 	secontext.cpp \
 	EncryptInplace.cpp \
+	MetadataCrypt.cpp \
 
 common_c_includes := \
 	system/extras/f2fs_utils \