Convert SnapshotStatus to proto

Also, add a "name" field to SnapshotStatus, and delete
the "name" arg from CreateSnapshot / WriteSnapshotStatus.
ReadSnapshotStatus will warn if the name mismatches from
the file name, and auto-correct it.

Test: libsnapshot_test

Change-Id: I725cf39c07684b100b140a8a21ea9d23ab9d2241
diff --git a/init/Android.mk b/init/Android.mk
index 62e452f..8fc44da 100644
--- a/init/Android.mk
+++ b/init/Android.mk
@@ -113,6 +113,7 @@
     libbacktrace \
     libmodprobe \
     libext2_uuid \
+    libprotobuf-cpp-lite \
     libsnapshot_nobinder \
 
 LOCAL_SANITIZE := signed-integer-overflow