Add property to prevent commit for Vts test

am: 3f1ce062d5

Change-Id: Ia742cb1ff865f5fd7b13843e72ee5309d90560db

Checkpoint.cpp

@@ -149,6 +149,11 @@ Status cp_commitChanges() {
     if (!isCheckpointing) {
         return Status::ok();
     }
+    if (android::base::GetProperty("persist.vold.dont_commit_checkpoint", "0") == "1") {
+        LOG(WARNING)
+            << "NOT COMMITTING CHECKPOINT BECAUSE persist.vold.dont_commit_checkpoint IS 1";
+        return Status::ok();
+    }
     sp<IBootControl> module = IBootControl::getService();
     if (module) {
         CommandResult cr;