Update dublin .gitreview

Update default.

Issue-ID: POLICY-1747
Change-Id: I0aa8727a4b3b7da1174a9a90708b8cd11802bd41
Signed-off-by: Pamela Dragosh <pdragosh@research.att.com>
diff --git a/.gitreview b/.gitreview
index d5613a8..7be271f 100644
--- a/.gitreview
+++ b/.gitreview
@@ -2,3 +2,4 @@
 host=gerrit.onap.org
 port=29418
 project=policy/api.git
+defaultbranch=dublin