Add supportsCheckpoint

This returns true if any entries in the fstab have checkpoint=
set.

Test: Call vdc checkpoint supportsCheckpoint. Should return 1
      iff an fstab entry has checkpoint=fs or checkpoint=block set
Bug: 111020314

Change-Id: Ic79bc96ded4da6605f73992dcff542e7cb50d705
diff --git a/Checkpoint.h b/Checkpoint.h
index eac2f94..64ceed3 100644
--- a/Checkpoint.h
+++ b/Checkpoint.h
@@ -23,6 +23,8 @@
 namespace android {
 namespace vold {
 
+android::binder::Status cp_supportsCheckpoint(bool& result);
+
 android::binder::Status cp_startCheckpoint(int retry);
 
 android::binder::Status cp_commitChanges();