[elektra] seed generic domains using global.domains_seeds (sapcc#8215)

Author: wagnerd3

openstack/elektra/ci/test-values.yaml

@@ -2,6 +2,8 @@ global:
   registry: "myImage"
   region: qa-de-1
   vaultBaseURL: vault.example.com/secrets
+  domain_seeds:
+    customer_domains: [ bar, foo, baz ]
 sentryDSN: "auto"
 monsoon_openstack_auth_api_password: bW9uc29vbi5vcGVuc3RhY2suYXV0aC5hcGkucGFzc3dvcmQ=
 two_factor_radius_secret: blablabla