bb: add testing manifest

This MR adds the testing manifest needed to enable bb testing.

testing_manifest.yaml

+bb:
+- project_id: 2326
+  repo: big-bang/product/packages/argocd
+  values_overrides:
+    upgradeJob:
+      image:
+        repository: '[[registry]]/[[repo]]'
+        tag: '[[tag]]'