Bump chart versions to publish them

Change-Id: Ie4a5869053742e7e6eabee11cada696b8e21014d
diff --git a/voltha/Chart.yaml b/voltha/Chart.yaml
index e8f2f89..6884e1b 100644
--- a/voltha/Chart.yaml
+++ b/voltha/Chart.yaml
@@ -14,7 +14,7 @@
 ---
 apiVersion: "v1"
 name: "voltha"
-version: "2.5.1"
+version: "2.5.2"
 description: "A Helm chart for Voltha based on K8S resources in Voltha project"
 keywords:
   - "onf"