Create change ref from ChangeInserter

Reduce some duplicated code. However, there are still a few special
snowflakes, so leave a flag to turn this off:
 - ReceiveCommits manages its own BatchRefUpdate. (It also doesn't
   even use PatchSetInserter for the new patch set case.)
 - ReviewProjectAccess updates the ref using VersionedMetaData, which
   I'm not going to touch for now.

Change-Id: I6f4f9fb8a6364627a737698d1001ad29ce8a981a

gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java

@@ -1766,6 +1766,7 @@ public class ReceiveCommits {
         .setMessage("Uploaded patch set " + ps.getPatchSetId() + ".")
         .setRequestScopePropagator(requestScopePropagator)
         .setSendMail(true)
+        .setUpdateRef(false)
         .insert();
       created = true;