Default registryCredential value results in bad private-registry secret

Bug

Description

If the default values.registryCredentials is used, a bad private-registry secret is created in every app namespace.

{"auths":{"registry1.dso.mil":{"username":"","password":"","email":"","auth":"Og=="}}}

The result is failed image pulls even if your cluster has credentials such as the registries.yaml in k3s.

Steps to reproduce:

1. Start k3s with registries.yaml mounted.
2. Deploy flux2 and Big Bang version > 1.0.2.
3. Observe image pull errors on app containers.

BigBang Version

> 1.0.2