SEBA-752 fixing atests in voltha-1.7

Change-Id: Id99a24a72e35baa31096750bf7fb12424017124f
diff --git a/tests/atests/common/testCaseUtils.py b/tests/atests/common/testCaseUtils.py
index 1fe4f82..9b9b67d 100755
--- a/tests/atests/common/testCaseUtils.py
+++ b/tests/atests/common/testCaseUtils.py
@@ -171,4 +171,4 @@
 
 
 def discover_rg_pod_name():
-    return extract_pod_name('rg-').strip()
+    return extract_pod_name('rg0').strip()