Add support for checkpointing

Checkpointing uses a combination of files on the meta partition
and the checkpoint= fs_mgr flag. Checkpointed partitions will
revert to their starting state on reboot unless checkpoint commit
is called.

Test: Run vdc commands, check file on metadata
Change-Id: Icba16578608a6cbf922472e9d4ae5b8cf5f016c6
diff --git a/VoldNativeService.h b/VoldNativeService.h
index dacf712..6739abc 100644
--- a/VoldNativeService.h
+++ b/VoldNativeService.h
@@ -118,6 +118,13 @@
 
     binder::Status mountExternalStorageForApp(const std::string& packageName, int32_t appId,
                                               const std::string& sandboxId, int32_t userId);
+
+    binder::Status startCheckpoint(int32_t retry, bool* _aidl_return);
+    binder::Status needsCheckpoint(bool* _aidl_return);
+    binder::Status commitChanges(bool* _aidl_return);
+    binder::Status prepareDriveForCheckpoint(const std::string& mountPoint, bool* _aidl_return);
+    binder::Status markBootAttempt(bool* __aidl_return);
+    binder::Status abortChanges();
 };
 
 }  // namespace vold