Add property to prevent commit for Vts test

Old approach (do not start class main) does not work because when
testings userdebug GSI on user system, adb does not start until the
framework starts.

Bug: 134126407
Test: Test passes with userdebug GSI on user Taimen
Change-Id: I20441964dbc7b6ad5b445fa17a1374c1282bbbd8
diff --git a/Checkpoint.cpp b/Checkpoint.cpp
index 19c1f3c..a3d78e7 100644
--- a/Checkpoint.cpp
+++ b/Checkpoint.cpp
@@ -139,6 +139,11 @@
     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;