Applying a ServiceTemplate to both Feature and Admin

Now that we have Service Templates the Couchbase CRD is free from defining every configurable attribute of a service.  One potential downside to this is that users wanting to move from the old way to new way might find themselves creating duplicate templates for both Admin and Feature services. 

Given the templates are already split, I'm thinking we can add an attribute to adminFeatureServiceTemplate such as 'useFeatureSpec'  which basically applies the attributes from one to another? Or vice versa?  I'm assuming having a 3rd generic template isn't the way since we'd get into overrides and priorities on what to pass along. 

Lastly, for what it's worth, this is easy enough to do have as in attribute in helm if it doesn't need to be done in operator.