Fix: draft patch set is published by cherrypicking

If a draft patch set is cherrypicked onto the same destination
change, i.e. as a shortcut to rebasing, the newly created patch
set is not draft.

Set the draft status of the newly created patch set to the same
as the source patch set.

Change-Id: I1e6e123171ee4257a784ab79f520810975b45644
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/change/CherryPickChange.java b/gerrit-server/src/main/java/com/google/gerrit/server/change/CherryPickChange.java
index 1e748d9..e129432 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/change/CherryPickChange.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/change/CherryPickChange.java
@@ -196,8 +196,10 @@
     final PatchSetInserter inserter = patchSetInserterFactory
         .create(git, revWalk, refControl, currentUser, change, cherryPickCommit);
     final PatchSet.Id newPatchSetId = inserter.getPatchSetId();
+    final PatchSet current = db.patchSets().get(change.currentPatchSetId());
     inserter
       .setMessage("Uploaded patch set " + newPatchSetId.get() + ".")
+      .setDraft(current.isDraft())
       .insert();
     return change.getId();
   }