init: Add first-stage init support for snapshot-based partitions.

Note that /metadata must now be mounted before CreateLogicalPartitions()
is called. This is because SnapshotManager overrides the default
partitioning scheme, and the only way to tell if a SnapshotManager is
needed is via the metadata partition.

Bug: 139204329
Test: manual test
Change-Id: I812df6c4c0d4d8753b1516f63dc70c5bc3e1c09c
diff --git a/init/Android.mk b/init/Android.mk
index 006e1bf..d7258a7 100644
--- a/init/Android.mk
+++ b/init/Android.mk
@@ -114,6 +114,7 @@
     libbacktrace \
     libmodprobe \
     libext2_uuid \
+    libsnapshot_nobinder \
 
 LOCAL_SANITIZE := signed-integer-overflow
 # First stage init is weird: it may start without stdout/stderr, and no /proc.