splitting voltha-sanity-system tests between repos

Change-Id: I966d8fa587c744e559e80e71cd72520e07f13677
diff --git a/jjb/defaults.yaml b/jjb/defaults.yaml
index 9ed426c..a87efc1 100644
--- a/jjb/defaults.yaml
+++ b/jjb/defaults.yaml
@@ -71,6 +71,7 @@
     modern-branches-regexp: '^(master|cord-7.0|cord-6.1|cord-6.0|seba-1.0)$'
     platform-branches-regexp: '^(master|cord-7.0|cord-6.1)$'
     seba-branches-regexp: '^(master|cord-7.0|seba-1.0)$'
+    voltha-stablization-branch: '^(voltha-2.1)$'
 
     # matchs all project repos
     all-projects-regexp: '.*'